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OBSERVATIONS ON FISH SCALES 


By T. D. A. Cockerell 


From BULLETIN OF THE BUREAU OF FISHERIES, Volume XXXII, 1912 
Document No. 779 : ; ; , ; ; ■ ; ; 77 ~ Issued ' October 25, 1913 



WASHINGTON : : : : : : GOVERNMENT PRINTING OFFICE : : : : : : ; ; ; , I933 













































OBSERVATIONS ON FISH SCALES 

By T. D. A. Cockerell 


From BULLETIN OF THE BUREAU OF FISHERIES, Volume XXXII, 1912 
Document No. 779 : : : : : : : : : : : : ; Issued October 25, 1913 




WASHINGTON 


: GOVERNMENT PRINTING OFFICE 


1913 


















n, OF D, 
NOV 10 1913 


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OBSERVATIONS ON FISH SCALES 

By T. D. A. Cockerell 

University of Colorado , Boulder , Colorado 






















































































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OBSERVATIONS ON FISH SCALES. 


By T. D. A. COCKERELL, 

University of Colorado, Boulder, Colo. 

INTRODUCTION, 

In a paper on “The Scales of Freshwater Fishes” (Biological Bulletin of the Marine 
Biological Laboratory at Woods Hole, Mass., vol. xx, May, 1911) I have given an 
account of the recent work on teleostean fish scales and have discussed some of the 
problems presented by the scales of freshwater fishes. Until recently it has been impos¬ 
sible to do much with the scales of marine fishes, owing to the difficulty of obtaining 
adequate materials. For the same reason very little was done on the spiny-rayed 
freshwater groups, the Percidae, Centrarchidae, etc. During the summer of 1911, 
however, I was enabled to continue the work in the laboratory of the Bureau of Fisheries 
at Woods Hole, where the director, Dr. F. B. Sumner, afforded me every possible facility 
and put at my disposal a large series of fishes representing many families. I have also 
been very greatly indebted to the Bureau of Fisheries, through Dr. Hugh M. Smith and 
Dr. B. W. Evermann, for numerous and important specimens from the collections at 
Washington. At the National Museum Mr. B. A. Bean and Mr. A. C. Weed gave me 
much help and supplied scales of some important genera, while other very valuable 
materials were secured from the Museum of Comparative Zoology, through the kindness 
of Dr. S. Garman. As in former years, I have been indebted to Dr. Boulenger for some 
of the rarest forms. With all this the outlook has been greatly enlarged; but of course 
the results here reported are quite insignificant compared with those which will doubtless 
be attained, mainly by other workers, in the future. The whole subject is still in a pre¬ 
liminary stage, and when it is considered that the ideal program is no less than the exam¬ 
ination and description of the scales of every scaly fish, with figures of all the genera, it 
becomes evident that there is work ahead for an indefinite number of years. 

A few years ago an eminent European ichthyologist expressed the opinion that the 
detailed work on scales was a waste of time; for, said he, “We have other excellent 
characters on which to classify fishes, so why bother with scales?” Possibly this 
particular authority will never be converted to lepidology, but I do not believe anyone 
could spend much time in the minute study of scales without becoming convinced of 
their great value for purposes of identification and classification. Like all other struc¬ 
tures, they vary, and present characters of all degrees of significance and stability; in 


120 


bulletin of the bureau of fisheries. 


the earlier work we made some mistakes because of poor judgment in these matters. 
The correct estimation of the importance of particular scale characters can only come 
with experience, and if through lack of it some unsound opinions are expressed in this 
paper, the fact should not be used as an argument against the study of scales. 

I have adopted, for the purposes of the present paper, the classification given by 
Dr. D. S. Jordan in his recent (1907) work “Fishes,” pages 757-771. It is only necessary 
to compare the classification in recent standard works by Jordan, Boulenger, and Good¬ 
rich, together with the essays of Regan, to perceive that there is still latitude for much 
difference of opinion in regard to fish taxonomy. Neither the authors cited nor anyone 
else would pretend to be able to present a classification which is nearly perfect, although 
many important matters are generally regarded as settled. In the slow approximation 
toward a system based on real relationship, lepidologists venture to think that they may 
have a part, and the present essay is written largely with' this end in view. 

The cost of the photographs used to illustrate this paper has been defrayed by a 
grant from the American Association for the Advancement of Science. 

Two corrections which I have had to make in this paper since it was written may 
be worth citing, as illustrating certain dangers of error, and at the same time bringing 
out clearly the general reliability of scales for identification. 

Under Boleosoma nigrum I had written that the scales from Osterville, Mass, (from 
the collection at Wood’s Hole), were so unlike those from Indiana that I supposed them 
to be wrongly determined. Dr. Sumner has since very kindly looked up the speci¬ 
mens, and reports that they are really Boleichthys fusiformis. In the case of Carpiodes 
velifer, I used scales from the fishes forming the basis of Juday’s record for Boulder 
County, Colorado, without making any study of the fishes themselves. I noted with 
surprise that they corresponded “very well with the scales of the common goldfish.” 
Dr. Max Ellis, going over the collection, has discovered that the specimens are in fact 
wild, dark-colored examples of the goldfish, Car as sins auratus. 

Class TELEOSTOMI. The true fishes. 

Subclass CROSSOPTERYGII. 

Order ACTINISTIA. 

CCELACANTHIDAJ (Fossil). 

Dr. A. S. Woodward (Catalogue of Fossil Fishes, pt. 2, pi. xiv) has figured the scales of Coelacan- 
thus. The figures are excellent, but unfortunately show only the apical (exposed) portion, which is 
ornamented with broad grooves running obliquely toward the middle line. Through the kindness of 
Dr. L. Hussakof, I have obtained the loan of several scales of Coelacanthus robustus Newberry, from the 
Carboniferous of Mazon Creek, Ill. These show that the scale is elongate in form, with a large basal 
region wholly free from grooves, and consisting entirely of very fine longitudinal fibrillae, exactly as in 
Amia. The scales are about 12 mm. long and 8 broad. 

There is a striking resemblance between the apical (exposed) area of Coelacanthus, with its grooved 
lines, and the same area in the South American characinid Lebiasina bimaculata Cuvier & Valenciennes. 


OBSERVATIONS ON FISH SCALES. 


121 


Order CLADISTIA. 

POLYPTERIDjE. 

The scales of Polypterus endlicheri Heckel from the White Nile (British Museum) are entirely of a 
dense bony consistence, the exposed surfaces rhombic or diamond-shaped with an enamel-like coating. 
The scales are produced into a long concealed process, and each has a peg or tooth fitting into a hole 
or socket in the next scale. Although Polypterus belongs to a very primitive group, its scales must be 
considered highly modified; the protection they afford may perhaps explain the survival of the genus. 
It is in Coelacanthus , not in Polypterus, that we get the real clue to the affinities of the crossopterygians. 

Subclass DIPNEUSTI. Lungfishes. 

Order CTENODIPTERINI. 

CTENODONTIffiE (Fossil). Comb-toothed Lung fishes. 

The large scales of Sagenodus from the Carboniferous of Mazon Creek, Ill. (American Museum of 
Natural History), almost entirely agree with those of the living Neoceratodus. Aside from the irregular 
radii, forming a network in the central part of the scale, both form and structure are very near to those 
of the bowfin, Amia; and both, except for the lack of grooves in the exposed region, approach Coela¬ 
canthus. The one important feature in which all these agree is the large concealed area consisting of 
longitudinal fibrillae. Among the Teleostei we find this retained only in the bonefishes, Albulidae. 

Order SIRENOIDEI. Sirenoid fishes. 

CERATODONTIDvE. Flatheads. 

Neoceratodus forsteri, from Queensland (British Museum), has very large elongated scales with 
longitudinal beaded fibrillae and a radial system of reticulation. (Science, May 26, 1911, p. 831.) 
The radial network and the tuberculate or beaded fibrillae distinguish these scales from those of Amia. 

LEPID0SIRENIDA5. Scaly sirenids. 

The scales of Lepidosiren and Protopterus are briefly described in Science, May 26, 1911, page 831. 
Although these fishes come from widely separated regions (South America and Africa) and undoubt¬ 
edly represent different subfamilies (Lepidosireninae and Protopterinae), their scales are almost exactly 
alike. There is a strongly developed radial network, as in the Osteoglossidae, and the surface is 
minutely tuberculate, the tubercles derived from beaded fibrillae. The scales are inclosed in the 
skin, and are circular or approximately so, not elongate as in Neoceratodus and Sagenodus. 

Subclass ACTINOPTERI. 

Superorder GANOIDEI. 

In this case I prefer to write “superorder,” rather than “series,” as the term defines the rank of the 
category in relation to others. 

Order GINGLYMODI. 

LEPISOSTElffiE. Gar pikes. 

The rhomboidal ganoid scales of the gar pikes Lepisosteus have a very close superficial resemblance 
to those of Polypterus, a case doubtless of convergence of type, due largely to the mechanical necessities 
of the situation. The scale of Lepisosteus is not so highly specialized as that of Polypterus, since it 
lacks the well-defined peg-and-socket arrangement. (For a further discussion of the scales of these 
genera, see Goodrich, Proceedings Zoological Society of London, November, 1907, p. 762-763.) 


122 


bulletin of the bureau of fisheries. 


Order HALECOMORPHI. 

AMIIDAi. Bowlins. 

I still write Amia and Amiidae for the bowfin, being unconvinced that the rules of nomenclature 
require the change which has been proposed. The scale of Amia has been discussed in several of my 
earlier papers (e. g., Smithsonian Miscellaneous Collections, vol. 56, no. 1, p. 1). It has simple longi¬ 
tudinal fibrillae, and no radial network. In its general structure it is not far from Ccelacanthus, or indeed 
very remote from Neoceratodus and Sagenodus. No comparison is possible between the scales of Amia 
and Lepisosteus, and it is Amia alone which points toward the Teleostei. 

Superorder TELEOSTEI. The bony fishes. 

Order ISOPONDYLI. The isospondylous fishes. 

I would change Jordan’s arrangement of families to the extent of placing the Albulidae first among 
the living groups, as undoubtedly the most primitive. It alone has the strictly longitudinal basal 



Fig. i. —Amia calva. 


Fig. 2. —Albula vulpes 
(Albulidae). Bureau 
of Fisheries. 


Fig. 3. —Elops saurus (Elopidae). 
Bureau of Fisheries. 



fibrillae, which are tuberculate as in the Dipneusti. It alone, also, has two transverse series of valves 
to the bulbus arteriosus instead of one, another primitive character. 


ALBULIDAE. Bonefishes. 


The scale of Albula is shown in text figure 2; that of Dixonina does not differ. In outline and 
general form these scales resemble those of Synodus and Lucius or Esox (pi. xxxv, fig. 19, 20), but 
these latter have transverse basal circuli. 


ELOPIDAJ. Ten-pounders. 

For a discussion of the scales of Elops see Smithsonian Miscellaneous Collections, volume 56, 
no. 3, page 3. Their structure shows nothing especially primitive; the basal circuli are very finely 
beaded, the lateral ones simple. The apical circuli, above the nucleus, break up into transverse 
labyrinthiform markings, the sculpture much coarser than that of the normal circuli. 

MEGALOPIDvE. Tarpons. 

Jordan makes a separate family for the tarpons, although on an earlier page of the same book he 
follows the more usual custom of referring them to the Elopidae. I am indebted to Mr. V. N. Edwards 
for a scale of Tarpon atlanticus (Cuvier & Valenciennes), from Woods Hole, Mass. It is of course very 
large (62 mm. long, and almost as broad), and is formed much as in Elops, differing, however, by having 
only three basal radii (12 to 20 in Elops), the basal margin broadly scalloped much as in Synodus. The 







OBSERVATIONS ON FISH SCALES. 


123 


scale is indeed curiously similar in form and structure to that of Synodus, though the nucleus is not 
so far apicad. The region above the nucleus is minutely roughened or tuberculate, and the apical 
circuli are longitudinal. The basal circuli are finely beaded. 

HIODONTIDAS. Toothed herrings. 

The scales of the moon-eye Hiodon tergisus are discussed in Smithsonian Miscellaneous Collections, 
volume 56, no. 3, page 3. They have much in common with Elops, but the wholly transverse fine 
circuli of the apical field are not at all modified above the nucleus. The basal radii are numerous and 
irregular, inclined to be divided into two groups, and the basal margin is undulate, not scalloped. The 
basal circuli are without distinct beading. The scale is of a cyprinoid type. 

CHIROCENTRID/E. Long herrings. 

The long herring, or dorab, Chirocentrus dorab (Forsk&l), from the Philippine Islands, has transverse 
circuli and radii, essentially as in Clupeidae, the radii usually angled in the middle. There are also 
irregular basal longitudinal radii, few in number, much as in the anchovy Stolephorus argyrophanus. 
On page 113 of volume xxiii of the Proceedings of the Biological Society, Washington, for “jive trans¬ 
verse circuli” read “jine transverse circuli,” and it is the basal, not the apical field, which has these 
more widely spaced circuli. Upon minute comparison I find that the whole arrangement, both circuli 
and radii, agrees essentially with Stolephorus argyrophanus, and hence in its scales Chirocentrus is to be 
compared with the Engraulidae rather than with the Clupeidae. The scale is, in fact, wholly as in the 
engraulids. 

ENGRAULIDIDjF. Anchovies. 

I alter Jordan’s arrangement by placing these before the Clupeidae, as being more primitive, at 
least as to the scales, and also nearer the chirocentrids. Dr. Max Ellis has prepared a paper fully dis¬ 
cussing the available material. Some of the species show an evident reticular network, in one case so 
well developed that the scale looks like that of some osteoglossid. 

CLUPEID^. Herrings. 

I here consider only the Clupeinae, of which I have examined nearly all the American genera. 
Two tribes are indicated, Brevoortiini, for Brevoortia, and Clupeini, for the other genera. In the men¬ 
haden, Brevoortia tyrannus (Eatrobe), the apical margin of the scale is produced into long parallel teeth 
with very slender ends. These teeth arise from a pellucid apical zone, and the intervals between them 
are prolonged basad as grooves for a distance about equal to the length of the teeth. Below these grooves 
are numerous small and short grooves looking like roots, the large grooves seeming to be the stems from 
which they arise. Below this the scale is entirely covered with very fine transverse circuli, and has 
in addition irregular pits and two transverse radii. The dentate scale margin is by no means peculiar 
to Brevoortia; it is quite distinct, for example in Alosa and Clupea, but the teeth are very irregular 
and by no means so long or tapering. In juvenile Alosa the margin is not dentate. The pitting seen 
in Brevoortia is also very strongly developed in some scales of the thread herring, Opisthonema oglinum 
(Le Sueur), from Woods Hole; it is evidently derived from evanescent transverse radii. In some scales 
of O. oglinum there are five transverse radii, all but the uppermost broken in the middle; there is then 
no pitting, but the well-pitted scales have only the upper radius. In the pilchard, Clupanodon pil- 
chardus, from Palermo, Italy (Bureau of Fisheries), there are seven or eight transverse radii, all widely 
broken in the middle except the first, the lower ones oblique, the whole reminding one of the ribs of 
the human skeleton seen from in front. The extremely fine circuli are strictly transverse, meeting the 
lateral margins at right angles. I find essentially the same in the West Indian sardine, Clupanodon 
pseudohispanicus Poey, from Woods Hole (pi. xxxv, fig. 18), but in two scales I notice that the 
circuli curve upward on one side only. 

Comparing Clupanodon with the sea herring, Clupea harengus (from Woods Hole and Sandy Island), 
two differences are at once apparent. In Clupea the transverse radii are commonly (though not uni¬ 
formly) entire, or not interrupted in the middle, whereas in Clupanodon they are (except the first) 


124 


BULLETIN OF THE BUREAU OF FISHERIES. 


quite regularly interrupted; in Clupea also it is common to find a pair of irregular apical radii, joining 
basally to form a sort of U. In Clupea the lateral circuli, following the trend of the transverse radii, 
reach the margin obliquely, not at right angles as in Clupanodon; this seems to be in some degree a 
matter of age, yet the large scales from Woods Hole, in which the obliquity of the circuli is very strongly 
marked, show growth lines delimiting various younger stages, and when less than half grown the circuli 
were already moderately oblique. It is a curious thing that the scales from Sandy Island (Bureau of 
Fisheries) have the transverse radii more numerous, much less regular, and interrupted at intervals, 
the circuli more transverse, in the young very little oblique, and the lower limit of the hyaline apical 
area straight or almost, whereas in the Woods Hole scales it is concave or even broad V-shaped. Are 
there two types of herrings, or is this individual variation ? 

The large scale of the shad, Alosa sapidissima, has been figured in Smithsonian Miscellaneous Col¬ 
lections, volume Lvi, no. i, page 2, and discussed at length in the Proceedings of the Biological Society 
of Washington, volume xxiii, pages 61-62. It is shown that the transverse radii are derived from the 
apical radial system, all stages of transition being visible. The adult Alosa scale has the circuli and 
radii at the sides very oblique; in some scales the radial system is very highly developed, with very 
numerous apical radii, and those about the middle of the scale variously anastomosing, forming an 
irregular network. There is, however, no approach to the type of network seen in some Engraulididae 
and better developed in Osteoglossidae. So far as the scale goes, Alosa must stand at the base of 



Fig. 4. —Brevoortia tyrannus (Clupeidae). Apical teeth. Bureau of Fisheries. 


the clupeine series, with Clupea close to it but a little more advanced. Clupanodon then represents 
a considerable further step in the direction of clupeine specialization, with the fixation of the more 
characteristic features. 

In Sardinella humeralis (Cuvier & Valenciennes), from Tampa, Fla., the scales differ conspicu¬ 
ously from Clupea , Clupanodon, Alosa, etc., in being much broader than long, the lower comers obtusely 
almost rectangular. The circuli are strictly transverse, not oblique; there are two widely separated 
entire transverse radii, and part of a third one forming a small reversed broad V on the lower margin; 
the lower margin of the hyaline area is slightly concave. These scales are perhaps not adult; they 
resemble in many ways the immature scales of Alosa. 

The scales of the alewives, Pomolobus, have the lateral circuli moderately oblique, except in the 
young; the undulating transverse radii distinctly rather widely spaced, often broken in the middle 
but not regularly or widely so, as in Clupanodon. Two species before me are rather easily distinguished: 

Pomolobus aestivalis (Mitchill). Glut herring. Scales about as long as broad; lower margin of 
hyaline area concave. 

Pomolobus pseudoharengus (Wilson). Branch herring. Scales conspicuously broader than long; 
lower margin of hyaline area straight. In a former paper I said I did not know how to distin¬ 
guish young scales of P. pseudoharengus from young of Alosa sapidissima. However, in the 
Alosa the lower margin of the hyaline area is uniformly distinctly concave; in P. pseudoharen¬ 
gus it is straight or even convex, except in the very earliest stage, when the diameter is much 
less than a millimeter. Reviewing the Clupeinae, it appears that we may place Alosa at the 
base of the series, and just above it Clupea. Then Clupanodon stands at the end of a branch, 
from the side of which springs Opisthonema, leading directly toward Brevoortia. From an earlier 
part of the same branch may arise Pomolobus, and somewhere near here Sardinella. All this 
is based on the scales, and must of course be modified when the structures are considered. 









observations on fish scales. 


125 


The character given in Jordan and Evermann’s key for all the clupeines except Brevoortia, “scales 
with their posterior [apical] margins entire and rounded” is not accurate, although Brevoortia scales are 
readily separated from the others by their long weak teeth. 

PHRACTOKFMID#. 

Phractolcemu 9 is a living African fresh-water genus; Jordan has the family printed by error in italics, 
as extinct. The scales of the only known species are described in the Proceedings of the Biological 
Society of Washington, volume xxiii, page 112, and figured in Biological Bulletin, volume xx, plate 
hi, figure 17a. They strongly suggest certain of the Characinidae. 

OSTEOGLOSSIDiE. Bony-tongued fishes. 

There are at least two subfamilies, Osteoglossinae ( Osteoglossum and Scleropages ) and Heterotinae 
(Heterotis ). The scales of this group, remarkable for their regular network and beaded circuli (primi¬ 
tive characters recalling the Dipneusti), have been discussed in the Proceedings of the Biological Society 
of Washington, volume xxiii, page hi, and volume xxiv, page 39; Science, May 26, 1911, page 831; 
and Heterotis is figured in Biological Bulletin, volume xx, plate hi, figure 20. Mr. W. M. Mann has 
kindly sent me scales of the Amazon bone-tongue, Arapaima gigas (Cuvier), which Eigenmann makes 
the type of a distinct family, Arapaimidce. They are about 78 mm. long and 55 broad, superficially 
like those of Neoceratodus. The exposed part has a very coarse labyrinthoid rugosity. The concealed 
part has elongated reticulations and beaded circuli; the reticulation very irregular and not nearly so 
well developed as in Osteoglossum. The scale is really very near to that of the Nile bone-tongue, 
Heterotis. 

PANTODONTIDAJ. Pantodonts. 

Living African fishes, only one species known. The scales are described in the Proceedings of the 
Biological Society of Washington, volume xxm, page 112, and figured in Biological Bulletin, volume 
xx, plate m, figure 18. The circuli are strongly beaded. 

N0T0PTERIDA5. Finbacks. 

Fresh-water fishes of the Ethiopian and oriental regions, considered by Boulenger to be nearest to 
the Hiodontidae. The scales of the African Notopterus afer Gunther are described in the Proceedings 
of the Biological Society of Washington, volume xxiii, page 112. In this place I have remarked on the 
resemblance of the scales to those of Gadus. This is certainly true as regards shape and general appear¬ 
ance, but on close comparison it is seen to be wholly superficial. In the gadines the numerous fine 
radii extend in all directions from the nucleus; in Notopterus, except for a series of striae just below the 
apical margin, they are wholly basal, and only the central ones reach the nuclear region. In Notopterus 
these radii are only about half as dense (close) as in Gadus, but on the other hand the circuli are much 
denser. The circuli of Notopterus are not at all beaded. 

SALMONIDAJ. Salmon, trout, etc. 

Very good figures of Salmo scales have been published by Mr. J. Arthur Hutton in his pamphlet on 
“Salmon Scale Examination and its Practical Utility” (London, 1910). He shows that the life of the 
fish affects the growth of the scales, so that by examining the scales it is possible to determine the 
approximate age, the time spent in the river and in the sea, and other important facts. The salmonoid 
scales before me are the Atlantic Salmon, Salmo salar Linnaeus, Woods Hole, Mass.; the golden trout, 
S', roosevelti Evermann, cotype, Mount Whitney, Cal.; Coulter’s whitefish, Coregonus coulterii Eigen¬ 
mann & Eigenmann, cotype, Kicking Horse River, Field, British Columbia; the brook trout, Salvelinus 
fontinalis (Mitchill), Woods Hole, Mass.; the blueback or red salmon, Oncorhynchus nerka (Walbaum), 
Wallowa Lake, Oreg. (J. J. Stanley). I have figured the scale of the blackfin, Leucichthys nigripinnis 
(Argyrosomus nigripinnis Gill), in Biological Bulletin, volume xx, (1911), plate 1, figure 2. The scales 
of Salmo are more or less oval, with well developed concentric circuli, which variously fail in the apical 
region; the radii are absent. Scales of Salvelinus and Oncorhynchus are essentially the same; with 


126 


BULLETIN OF THE BUREAU OF FISHERIES. 


the material before me I am not able to make any satisfactory table for their separation. Leucichthys 
nigripinnis is distinct by the evident laterobasal angles. Coregonus coulteri scales are about 1.5 mm. 
long by 2 broad, varying to approximately circular, but apparently never (at least on the middle of the 
side of the fish) longer than broad, as is usual in the Salmo group. The circuli are very widely spaced, 
and there are rather obscure indications of laterobasal angles. These Coregonus scales are perhaps 
immature. It is probable that the following characters are valid for the subfamilies: 

Coregoninae, Whitefishes and Lake Herring. —Scales as broad or broader than long, with 
laterobasal angles more or less developed. 

Salmoninaj, Salmon, Trout, etc. —Scales nearly always longer than broad, without laterobasal 
angles. Of these, the Coregoninae must apparently be considered the more primitive. 

ARGENTINA. Smelts. 

Osmerus mordax Mitchill, from Menemsha Bight, Mass. (J. T. Field), has approximately circular 
scales about 2.5 mm. diameter, without radii. The circuli are very widely spaced except basally, where 
they are crowded; they are obtusely angled in the middle line above and on each side. The laterobasal 
comers are very obtuse but evident; the basal middle is broadly produced into a rounded lobe, which is 
usually emarginate. The nucleus is far toward the base of the scale, approximately on a level with the 
laterobasal comers. 

This scale is in general related to that of the Coregoninae, but is readily distinguished by the position 
of the nucleus. 

SYNODONTIDAJ. Lizard-fishes. 

Rather large semicircular cycloid scales; nucleus a little ( Trachinocephalus ) or considerably (Syno- 
dus) above the middle; very strong basal plicae (2 or 3 in Trachinocephalus, 3 or 4 in Synodus ); circuli 
normal, quite dense in Synodus, rather widely spaced in Trachinocephalus, the apical ones longitudinal; 
laterobasal angles evident but obtuse; apical marginal area broadly thin and sculptureless, in the manner 
of certain clupeids, but the submarginal area, or marginal area of the scale proper, sculptureless, except 
for scattered punctiform markings, its margin irregularly minutely dentate (more evidently in the 
Synodus), as if very irregularly broken. Scales of Synodus yellowish, of Trachinocephalus colorless. 

The species studied are Trachinocephalus myops (Forster), the ground spearing, from Woods Hole, 
Mass., and Synodusfaetens Linnaeus, the lizard fish (pi. xxxv, fig. 19), from Galveston, Tex. (Evermann). 
The apical structure seems to be prophetic of the acanthopterygian type of ctenoid scale; in the Gerridae 
(Xystcema cinereum Walbaum) the apical margin is very thin, covered with minute shadowy diamond¬ 
shaped markings, the vestiges of the disappearing teeth; no such vestiges can be seen in the Synodontidae, 
although the superficial appearance is similar. Jordan notes of Synodontidae that the head is scaly, 
“ a character rare among the soft rayed fishes, ’ ’ but usual among Acanthopterygians. 

MAUROLICIDAJ. 

Maurolicus pennanti (Walbaum), from Woods Hole, Mass., has easily deciduous, extremely thin 
scales, with widely spaced evanescent circuli. According to Jordan, the Maurolicidae are scaleless, but 
no doubt the specimens examined had lost their scales. Dr. F. B. Sumner tells me that he carefully 
worked over the Woods Hole species and noted the presence of scales. 

In the related family of Myctophidae, the lantern fishes, the scales of Myctophum resplendens, as 
figured by Gunther, are better developed; broad, cycloid, regularly circulate, nucleus nearly central, 
about six strong basal folds. They are rather like those of Cypsilurus. 

Order APODES. Apodal fishes. 

Suborder EnchelycEphali. The eels. 

ANGUILLIDAJ. Fresh-water eels. 

The scale of the common eel ( Anguilla rostrata or chrisypa) is a remarkable structure, very unlike 
any of the scales discussed above. It is 2 mm. long, or slightly over, narrow, and with rounded ends, 
approximately sausage-shaped in outline. The nucleus is central, and on an extremely fine reticulated 


OBSERVATIONS ON FISH SCALES. 127 

framework are arranged concentric rings of oval elements, which are hyaline with narrow dense margins 
These oval bodies are actually capable of being detached, or more strictly speaking their surface layers 
are detachable, retaining their original form and appearance. 



Fig. 5. —Anguilla rostrata (Anguillidae). Details of sculpture. Bureau of Fisheries. 



Fig. 6 .—Synaphobranchus pinnalus (Synaphobranchidae). Bureau of Fisheries. 



Fig. 7. —Ichthyophis glutinosus (Caeciliidae). Amphibian scale. British Museum. 

SYNAPHOBRANCHIDAE. 

In Synaphobranchuspinnatus (Gronovius), a deep-sea eel, the scales are shaped much as an Anguilla, 
but not so elongate, and very much smaller, the length about two-thirds of a millimeter. The general 
appearance and detailed structure are shown in the figure. In this scale we get a clue to the evolution 




128 


bulletin of the bureau of fisheries. 


of the Anguilla type, the structure, with its upper and lower layers, being much the same; but the 
upper layer exhibits more or less quadrangular spaces, due to the crossing of the radial and circular 
systems. The specialization of detachable oval plates does not exist, but it is possible to see how it 
might arise from a type resembling Synaphobranchus. 

Although I have found nothing among the primitive fishes which seemed to lead toward the eels, 
there is a distinct resemblance, I believe not altogether superficial, to be observed in the scales of the 
caeciliid amphibians. I am greatly indebted to Dr. Boulenger for material of Ichthyophis glutinosus 
(see text fig. 7). Here the elongate quadrangular spaces are arranged like bricks in a wall, but in con¬ 
centric circles, while the center of the scale is reticulate and minutely tuberculate, quite closely simu¬ 
lating the condition in the Lepidosirenidae. Thus in a remote and general way, Ichthyophis scales 
connect those of the eels with those of primitive fishes, suggesting that the eel type is really a very 
ancient one, not derived from any of the groups of fishes nearly associated with if in the classification. 

In this connection the extinct Archencheli, considered primitive eels with isospondylous traits, 
become very important. I have never seen Urenchelys, but Dr. A. S. Woodward says of it, “scales 
rudimentary”; and under U. avus A. S. Woodward, he says of one specimen, “there are no traces of 
scales,” but of another, “the brownish impression of the soft parts of the fish is curiously mottled, as if 
there were indications of small, rudimentary quadrangular scales.” Looking in the opposite direction, 
we find an unexpected revival of the ichthyophoid type of scale, at least as regards the quadrangular 
areas, in the gadid Brosmius brosme, the cusk. The fine radii are broken so that, as in Ichthyophis, the 
bricklike spaces are largely laid in alternate fashion, not one directly above the other. In the pol¬ 
locks, Pollachius and other genera, however, the radii are essentially continuous, and one can hardly 
doubt that the Brosmius scale was derived from a Pollachius- like type. In this connection it is worth 
while to note that Sphyrcena picuda has a scale pattern practically identical with that of Pollachius. 

All things considered, it must be admitted that the eel type of scale could have been derived from 
something of the Sphyrcena or gadid pattern, and hence it is not necessarily primitive. The resemblances 
noted are, however, interesting, and may not be without some significance. 

According to Boulenger, the scales of the Muraenolepididae resemble those of the Anguillidae. 

Order OSTARIOPHYSI. 

Suborder Heterognathi. 

CHARACIDA5 (CHARACINIDAJ). Characins. 

The scales of the African species have been discussed in Smithsonian Miscellaneous Collections, 
volume 56, no. 1. Those of the South American genera form the subject of a lengthy paper to be 
published by the Carnegie Museum. This also includes the Erythrinidae. 

Suborder Eventognathi. 

CYPRINIDAJ. Minnows and carps. 

The scales of this family have been discussed in numerous papers. I give here a list of the genera 
which I have examined, with references to literature and some additional information and figures. 

(A) AMERICAN GENERA. 

It is doubtful whether any genera of Cyprinidae are common to America and the Old World, 
except, of course, those introduced by man. 

A bramis auett. Amer., the shiner=Notemigonus. 

Acrocheilus Agassiz, the chisel-mouth. Proc. Biol. Soc. Wash., xxn, p. 210 (subfamily Chondros- 

tominae). 


OBSERVATIONS ON FISH SCALES. 


129 


Agosia Girard, the western dace. Proc. Biol. Soc. Wash., xxn, p. 157. Girard, Ichthyology of the 
Mexican Boundary Survey, pi. xxvn, fig. 6-8 ( notabilis=oscula ); pi. xxvn, fig. 10-12 (oscula); 
pi. xxviii, fig. 6-8 ( chrysogaster ); pi. xxvm, fig. 2-4 ( metallica-chrysogaster ). Girard’s figures show 
that the scales of the subgenera Apocope and Agosia are essentially of the same type, more or less 
elongate, with basal as well as apical radii. According to the figures, the scales of A. chrysogaster 
are distinctly different from those of A. metallica, the former rounded, the latter quadrate. Is it 
not probable that there are two species or races? 

Algansea Girard. (PI. xxxn, fig. 3.) Proc. Biol. Soc. Wash., xxiv, p. 213 {A. sallcei)', Zoologischer 
Anzeiger, xxxvi, p. 476 ( tincella ); Biological Bulletin, xx, p. 373 ( tincella , ajffinis, stigmatura). 
Girard figures the scales in Ichthyology of the Mexican Boundary Survey, pi. xxvn, fig. 2-4. They 
are of the same general type as those of Agosia , longer than broad, with basal as well as apical radii. 
According to the scales, A Igansea does not seem near to Hyhognathus (the scales of which are large and 
broad, without basal radii), but should be an herbivorous representative of the Agosia-Rhinichthys 
group, or related in some way to Temeculina. Among the herbivorous groups, it is by its scales 
nearer to the Chondrostominae and Chrosominae than to the Pimephalinae. May we not regard it as 
a modified chondrostomine, pointing somewhat in the direction of the Agosia group? In any case 
the scale characters must be considered relatively primitive and indicative of affinity with Old 
World types. 

Campostoma Agassiz, the stone-roller. Proc. Biol. Soc. Wash., xxn, p. 122. Girard, Ichth. Mex. 
Boundary Survey, pi. xxv, figures scales of C. ornatum, anomalum (as nasutum) and formosulum; 
they are all broad, with nucleus far basad of the middle, and apical radii only; the general type of 
Notropis and many other American genera. This genus is the type of a distinct subfamily, pecu¬ 
liar to America. 

Chrosomus Rafinesque, red-bellied dace. Biol. Bulletin, xx, p. 370, pi. 1, fig. 5; Proc. Biol. Soc. 
Wash., xxn, p. 121. Scale broader than long, with radii all around; the type that of the European 
Phoxinus. An isolated genus in America. 

Cliola Girard. Proc. Biol. Soc. Wash., xxn, p. 189 (C. smithii). Girard, Ichth. Mex. Boundary 
Survey, pi. xxxi, fig. 22-24 (velox=vigilax). The scales are broad, with about 19 apical radii in 
C. smithii, about 8 or 9 (according to Girard’s figures) in vigilax. The genus seems to stand between 
Pimephales and Notropis. 

Cochlognathus Baird & Girard. Girard, Icth. Mex. Boundary Survey, pi. xxxv, fig. 15-17, shows 
very broad scales with subbasal nucleus, the radii only apical, about 10 or 12, not nearly reaching 
the nucleus. According to the figures the basal margin is strongly convex, not straight as shown 
in Cliola vigilax. Thus the base of the scale is practically as in Lavinia, while that of C. vigilax 
may be compared with Ericymba or Phenacobius. 

Couesius Jordan, the chub-minnow. Proc. Biol. Soc. Wash., xxn, p. 159. Near to Semotilus; apical 
circuli angulate in the middle. 

Ericymba Cope. Proc. Biol. Soc. Wash., xxn, p. 162, pi. m, fig. 1; Biological Bulletin, xx, p. 374, 
pi. v, fig. 28 (normal scale) and fig. 29 (latinucleate scale). 

Exoglossum Rafinesque, the cut-lip. Proc. Biol. Soc. Wash., xxiv, p. 213. Scale resembling that of 
Mylocheilus. 

Gila Baird & Girard, the bony-tail. Biological Bulletin, xx, p. 374, pl.v, fig. 30 (scale of young G. 
robusta ); Girard, Ichth. Mex. Boundary Surv., pi. xxiv, fig. 10-12 ( grahami=robusta ); pi. xxxm, 
fig. 8-10 (emorii=elegans). The mature scale is more or less elongate, with a distinct basal lobe, 
the base being in general like that of the shorter scale of Lavinia. A Gila about 9^ inches long, 
collected by Messrs. E. R. Warren and J. W. Frey in the Bear River at Lily, Routt County, Colo., 
June 30, 1909, appears to be G. seminuda Cope & Yarrow. The caudal peduncle is almost 13 mm. 
in depth, the base of the caudal fin 20 mm. The fish is a typical Gila, and G. seminuda appears to 
have been based on an immature specimen. The ventral surface is without scales. Peritoneum 
rather dilute black, not spotted. Posterior division of air bladder large and broad, its breadth 16 
mm. Scales in lateral line about 96; the scales are elongate, with parallel, even concave sides; 

89970 0 —13-2 


132 bulletin of the bureau of fisheries. 

Richardsonius gibbosus is figured by Girard as having radii all around the scale, apical, lateral, and 
basal, and a scale from the abdominal region has a polygonal pattern in the nuclear field. Accord¬ 
ing to the scales, therefore, this fish agrees with Temeculina. Placed in Richardsonius , the name 
gibbosus (Gila gibbosa Baird & Girard 1854) has priority over nigra Cope 1876, and intermedia Girard 
1856, the latter said by Gilbert & Scofield (1898) to be identical. The name gibbosus is not a 
homonym if the fish is not placed in Leuciscus. According to Girard’s figures, R. pulchellus has 
occasional poorly defined basal radii, but the whole appearance is very different from that of R. 
gibbosus. The scale of R. intermedius (there regarded as distinct from gibbosa or nigra) was briefly 
described in Proceedings of the Biological Society of Washington, volume xxn, page 159, and 
was found to fall in the same immediate group as R. pulchellus (nigrescens ); this does not agree 
with Girard’s figures of gibbosus , but certainly his scales came from a much older fish. It remains 
to be seen whether R. intermedius is really distinct from gibbosus, but in view of the facts stated 
it will probably be best to follow Jordan & Evermann in so treating it. There is, however, a 
further complication arising from the publication of Gila gracilis Baird & Girard 1853, which 
Gilbert & Scofield (1898) say is not G. robusta, but is “ Leuciscus intermedius .” The name gracilis 
is not a homonym if the fish is not referred to Leuciscus, and it has priority even over gibbosus, 
so that in any event Richardsonius gracilis (Baird & Girard) must be a valid specific name. Another 
change of nomenclature is required in the case of Richardsonius alicice. The name Tigoma gracilis 
Girard 1856, is not available; but Squalius copei Jordan & Gilbert 1880 is and the species becomes 
Richardsonius copei (Jordan & Gilbert). 

Rutilus auctt. Amer.= Myloleucus. 

Semotilus Rafinesque, chub. Proc. Biol. Soc. Wash., xxn, p. 162, pi. m, fig. 4 (S. corporalis and S. 
atromaculatus) . A western form of 5 . atromaculatus, obtained by Mr. H. G. Smith at Julesburg 
and Sterling, Colo., appears to be subspecifically distinct and may be known as 5 . atromaculatus 
macrocephalus (Girard). In its scales it approaches S. corporalis. 

Siphateles Cope. Proc. Biol. Soc. Wash., xxn, p. 161 (as Rutilus olivaceus) ; t. c. p. 217. 

Tiaroga Girard. Girard, Ichth. Mex. Boundary Survey, pi. xxviii, f. 12-14. The scales have radii 
all around, and are transversely oval in form, altogether in the manner of Chrosomus. 

Although there is still much to be learned about the scales of American Cyprinidae, the facts dis¬ 
cussed above indicate very well that our fauna is essentially distinct from that of the Old World, with, 
however, the nearest allies of Old World types mostly in the far West; also, I believe that any funda¬ 
mental separation of our genera into an herbivorous group with long intestine and a mainly carnivorous 
one with short intestine is artificial. The herbivorous group is to be divided into several which seem 
to be properly associated with corresponding groups in the carnivorous series. 

(b) old world genera. 

My material representing Old World Cyprinidae is almost wholly from the British Museum, which 
is herein abbreviated to B. M. 

Abramis Cuvier, breams. Proc. Biol. Soc. Wash., xxn, p. 211-213; Zool. Anzeiger, xxxvi, p. 478, 
fig. 3 (A. elongatus). 

Acanthorhodeus Bleeker. A. tcenianalis is a very deep-bodied fish from Shanghai (Swinhoe, B. M.); 
the scales, as usual in the Rhodeines, are extremely broad; length a little over 5 mm., breadth 
fully 8. The basal circuli are dense, those at the sides more widely spaced; the very numerous 
radii, all apical, are wavy, or more or less zigzag. The region of the radii is finely striate with 
lines of growth, and in the interradial spaces are spots due to a kind of pitting. (PI. xxxn, fig. 2.) 
Zool. Anzeiger, xxxvi, 477. 

Alburnus Heckel, bleak. Zool. Anzeiger, xxxvi, p. 477. (A. lucidus and filippii.) 

Amblyrhynchichthys Bleeker. A. truncatus from the Menam River, Siam (Royal Siamese Museum- 
B. M.), has subquadrate scales with very thin apical margins; length about 3%, with slightly over 


OBSERVATIONS ON FISH SCALES. 


133 


4 mm.; nucleus well basad of middle; laterobasal comers very distinct; basal margin thrown into 
two or three prominent folds; basal radii few, delicate and irregular; apical radii about ten, very 
slender, the outer ones broad outward; apical area with growth striae, but free from circuli (here 
agreeing with Gobio, Saurogobio, etc.); circuli very numerous, the lateral ones more widely spaced. 
The outline of the scale, especially the basal part, is practically as in Barbus mahecola (Biol. Bull., 
xx, pi. m, fig. 19), but the sculpture more resembles that of Gobio and its allies. 

Aspidoparia (Heckel) Bleeker. Zool. Anzeiger, xxxvm, p. 87, fig. 5. 

Ballerus Heckel. Proc. Biol. Soc. Wash., xxn, p. 212-213. 

Barbichthys Bleeker. Zool. Anzeiger, xxxvi, p. 252, fig. 2 and 3. The scale of B. Icevis from Siam 
is large, about 10 mm. long and 8 broad, with prominent though rounded laterobasal comers; 
basal margin thrown into two broad wave-like lobes; a single, median, basal radius; numerous 
apical radii, but only about four, which are strong, reaching the nuclear area, whereas in the mar¬ 
ginal region there are over 30; apical field with the circuli broken up, forming pustules; lateral 
and basal circuli dense and regular. The figures in the Zoologischer Anzeiger show the relation 
of the circuli to the pustules. 

Barbus Cuvier & Valenciennes, barbel. Proc. Biol. Soc. Wash., xxn, p. 157-158; xxm, p. 145-148, 
pi. m, fig. 1 ( B. chrysopoma), fig. 3 ( batesii ), fig. 4 ( barbus ), fig. 5 ( ksibi ), fig. 6 (pleurotaenia), fig. 9 
(grahami); Zool. Anzeiger, xxxvi, p. 479; Biol. Bulletin, xx, pi. m, fig. 19 {mahecola); Boulenger, 
Catalogue Freshwater Fishes of Africa, vol. n, p. 2, fig. 1 {bynni, pleurogramma, perince). The 
Barbus compressus mentioned in Proc. Biol. Soc. Wash., xxm, p. 146, is from Fort Stedman, Shan 
States, 3,000 feet (E. W. Oates; B. M.). This is B. compressus Boulenger, Ann. Mag. Nat. Hist., 
ser. 6, xii, 1893, p. 202; not B. compressus Day, Proc. Zool. Soc. Lond., 1869, p. 555. With Dr. 
Boulenger’s permission, I alter B. compressus Boulenger to B. compressiformis n. n. 

Barilius Hamilton Buchanan. Proc. Biol. Soc. Wash., xxm, p. 143-144, pi. m, fig. 10 {B. loati). 

Barynotus Gunther. I believe this generic name is preoccupied in Coleoptera. B. luteus from Schiraz 
(Marquis Doria; B. M.) has very large reddish quadrate scales, about 13 mm. long and broad; nucleus 
about 5 mm. from base; circuli very fine, about 10 or 12 basal radii and about 35 apical ones, the 
latter wavy and many of them imperfect. In size, color, and form this is like the scale of Semiplotus 
macclellandi, except that the latter is considerably broader than long. In detail there are rather 
important differences, though of degree rather than of kind. In the Semiplotus the basal radii 
are very few and weak, while there are numerous delicate but distinct lateral radii, represented only 
by a few irregular lines in Barynotus. In both the apical radii are wavy and the interradial spaces 
are tuberculate, but the tubercles are more prominent in Semiplotus and extend almost to the nucleus, 
whereas in Barynotus they do not go beyond the skin-covered area. 

Capoeta Valenciennes. (PI. xxxiv, fig. 13.) Proc. Biol. Soc. Wash., xxm, p. 149. According to Berg, 
C. steindachneri Kessl is a synonym of C. heratensis Keyserling. 

Carassius Nilsson, goldfish. Zool. Anzeiger, xxxvi, p. 480. 

Catla Cuvier & Valenciennes. Catla catla (Cyprinus catla Hamilton Buchanan; Catla buchanani Cuvier 
& Valenciennes) from Calcutta (F. Day; B. M.) has large elongate scales with rectangular basal 
comers; length 11, breadth 8 mm. The nucleus is about 4K mm. from the base; the base has five or 
six irregular but prominent radial folds; apical radii about 16, delicate, straight, many incomplete; 
lateral radii variable, when distinct similar to those of Semiplotus; basal circuli irregular and not 
so dense as usual; apical circuli distinct, longitudinal, the inner ones directed more or less mesad, 
approaching the condition so well developed in Cirrhina jullieni, but not nearly so extreme. Accord¬ 
ing to Day, Catla catla reaches a length of at least 6 feet, my material is from a much smaller fish. 

Chanodichthys Bleeker. C. pekinensis from Shanghai (Swinhoe; B. M.) has rather large broad-oval 
scales, about 10 mm. long and slightly over 8 broad; nucleus nearly central, circuli finely evanescent 
in the apical region, which is somewhat rugose; no basal or lateral radii, but about 21 apical, some 
incomplete. The scale examined is not symmetrical and probably not quite normal. 

Chela Hamilton Buchanan. (PI. xxxii, fig. 4-) Proc. Biol. Soc. Wash., xxm, p. 142, pi. m, fig. 12 (C. 
argentea). 

Chelcethiops Boulenger. Proc. Biol. Soc. Wash., xxm, p. 141-142, pi. 111, fig. 11 (C. bibie ). 


134 


bulletin of the bureau of fisheries. 


Chondrostoma Agassiz. (PI. xxxn, fig. 5.) Proc. Biol. Soc. Wash., xxn, p. 210; Zool. Anzeiger, xxxvi, 
P- 477 - 

Cirrhina Cuvier. Proc. Biol. Soc. Wash., xxm, pi. ill, fig. 8 (C. jullieni ). The scales of four species 
of Cirrhina, obtained from the British Museum, are so distinct as to suggest that they can not all 
be truly congeneric. 

Scale much longer than broad (length 9, breadth 7 mm.) with broadly rounded apex and squared 
base; circuli fine, wanting in the apical field, where they are replaced by coarse tubercles; 
basal radii about a dozen, delicate, many incomplete; apical radii few and irregular; nucleus 

a short distance basad of middle (Cutch, F. Day). C. mrigala Hamilton Buchanan 

Scale slightly longer than broad, or about as broad as long. 

Scale 9 mm. long, 8)4 broad; laterobasal comers distinct; nucleus considerably basad of middle; 
no basal radii; apical radii over 20, mostly well formed; circuli replaced by transversely 
elongate tubercles in the apical region covered by skin, but in the central region below this 

by vermiform markings.C. chinensis Gunther (Haslar collection). 

Scale 5% mm. long, 4)4 broad; laterobasal comers distinct; nucleus very far basad; a few weak 
submedian basal radii; apical radii about eight, distinct, wide apart; apical circuli very 
distinct, wide apart, sloping toward the middle (Stung-Strang, Paris Museum). 

C. jullieni (from type lot) 

Scale conspicuously broader than long (length 2^, width 3)4 mm.); nucleus far basad; basal radii 
about 20, very short, submarginal; apical radii over 20, not or hardly converging; circuli 
absent in apical region, but a small amount of tuberculation; broad nuclear area with fine 
very irregular reticulation; probably latinucleate scales (Kushk, Afghan Boundary Commission. 

C. afghana Gunther 

The scales of Cirrhina are in general (excepting C. afghana) much like those of Osteochilus or Labeo. 
Thus, as regards the sculpture of the apical field, C. jullieni may be compared with Labeo 
chrysophekadion, while C. mrigala and C. chinensis may be compared with Labeo sindensis, etc. 
May we not suppose that the groups of Osteochilus and Cirrhina have arisen from different groups 
of Labeo? 

Cosmochilus. I have a lateral line scale of C.falcifer, a very large fish from Sarawak, Borneo (C. Hose; 
B. M.). The scale is of the quadrate type, strongly orange tinted, about 20 mm. long and broad; 
lateral line canal bifid at the apical end; nuclear field extremely large, granular; basal radii very 
numerous, but wholly marginal and submarginal; apical radii very numerous, irregular, wavy; no 
circuli in apical field. C. harmandi from the Menam River, Siam (Royal Siamese Museum; B. M.) 
is represented by much smaller, pallid scales, about 7 mm. long and 6 broad, but of the same sub¬ 
quadrate form. Both basal and apical radii are fewer and more irregular, the basal longer, the 
apical wavy. Except for the size and minor details, the scales of the two species are wholly of the 
same type. 

Crossocheilos Bleeker. ( Crossochilus auctt.) I follow the British Museum labels, but Day refers C. 
latia and C. reba to Cirrhina. The scales before me are separable as follows: 

Scales large and elongate (length about n )4 mm., breadth about 6 ) 4 ), parallel-sided; circuli dense, 
those of the apical field transformed into tubercles in part, but toward the nucleus into vermi¬ 
form lines, and in the extreme apical region wholly wanting; nucleus only about 3 mm. from 
base; three or four distinct basal folds; apical radii numerous, more or less wavy, converging 
toward the middle; lateral radii delicate, variable, usually distinct (Madras, F. Day; B. M.). 

C. reba (Hamilton Buchanan) 

Scales smaller and much less elongate. . 

1. Scales evidently longer than broad.. 

Scales not or little longer than broad.3 

2. Basal margin gently convex, not wavy; laterobasal comers more rounded; basal radii very few 

and feeble; apical radii numerous, parallel; scale (not adult) about 5)4 mm. long and 4 broad 

(Simla, F. Day; B. M.).C. latia (Hamilton Buchanan) 

Basal margin wavy or broadly crenate; laterobasal comers sharper; basal radii very irregular, 
but distinct; apical radii numerous, many imperfect; nucleus about i>4 mm. from base; 
scale about 7 mm. long and 6 broad. (Java; B. M.). C. oblongus 

3. Nucleus less basad (i)< mm. from base in scale 5 mm. long and 4)4 broad); middle interradial 

(apical) region strongly tuberculate (Ningpo, F. W. Styan; B. M.). 5 . styani Boulenger 

Nucleus more basad; middle interradial region not tuberculate (Cashmere, T. C. Jordon; B. M.) 

C. barbatulus 










OBSERVATIONS ON FISH SCALES. 


135 






C. reba seems to stand apart from the others. Day says of C. latia, “this fish has much the character 
of a loach or of a Discognathus , adhering to stones in the beds of rivers.” Superficially the scales 
of C. reba look like those of Rohita lineata, but they are very different in detail, having a different 
apical field and the nucleus very much more basad than in Rohita. 

Cutter. This genus has rather small (about 4 mm. diameter) circular scales, with a central nucleus, 
rather few and weak apical radii, and no basal. The basal circuli are very dense. I have two 
species from the British Museum; C. ilishceformis from Kiu Kiang (Styan) and C. erythropterus 
Basilewsky from the River Keroulen, Mongolia (Chaffanjon). They are very much alike, but in 
erythropterus the apical radii are more distinct, and the apical margin is crenate. (PI. xxxiv, 

fig. 14.) 

Cyprinus Linnaeus, carp. Zool. Anzeiger, xxxvi, p. 480, fig. 2 (p. 478). The figure represents the 
hybrid C. kollarii. 

Dangila Cuvier & Valenciennes. From the British Museum I have the scales of three species: 

Scales large, much longer than broad (length 16 mm., breadth 10); strongly orange-tinted; parallel¬ 
sided; nucleus far basad; weak radii all around; middle apical region strongly tuberculate (in 

a deep place in the cavery, Salem, Capt. Mitchell). D. leschenaultii 

Scales much smaller, not longer than broad; not orange-tinted.2 

1. Apical field distinctly tuberculate; scale about 5 mm. long and broad. (Deli, Sumatra, Moesch.) 
D. kuhlii (cf. Zool. Anzeiger, xxxvi, p. 478, where for gobiiform read gobioniform.) 

Apical field merely striate; scale about 7 mm. long and broad (mouth of Patani River, Annandale 
& Robinson). D. cuvieri 

Danio Hamilton Buchanan. Type of subfamily Danioninse. Zool. Anzeiger, xxxviii, p. 85 , fig. 1 , 2 ; 
(D. devario and D. cequipinnatus.) 

Diptychus Steindachner. D. maculatus Steindachner from Nepaul (F. Day; B. M.) was examined, 
but no scales were found; the skin is very thickly beset with small spots of ferruginous pigment. 
According to Day, there are small scattered scales, which I evidently overlooked. 

Discognathus Heckel. Proc. Biol. Soc. Wash., xxiii, p. 149-150. The species described belong to the 
subgenus Garra Hamilton Buchanan. 

Engraulicypris Gunther. Neobola Vinciguerra is now regarded by Boulenger as a synonym. Proc. 
Biol. Soc. Wash., xxiii, p. 143 ( Neobola) and 144. 

Gnathopogon Bleeker. I have examined G. gracilis (Capoeta gracilis) from Superghan, Nalzow Chai 
River (R. T. Gunther; B. M.), and have given some account of it in Proc. Biol. Soc. Wash., xxiii, 
p. 149. The scales are about 4mm. long and 3^ broad; nucleus well basad of middle; laterobasal 
comers prominent; basal radii irregular, few and very feeble- apical radii distinct, about 15, with 
strong tubercles between. 

Gobio Cuvier, gudgeon. Zool. Anzeiger, xxxvi, p. 477-478; Biol. Bulletin, xx, pi. v, fig. 27. 

Gymnocypris Gunther. I examined G. waddellii Regan (Yamdok Lake, Tibet, 14,800ft., L. A.Waddell; 
B. M.) but found no scales. The skin is sepia brown with darker, reddish dots. 

Hemibarbus Bleeker, Proc. Biol. Soc. Wash., xxiii, p. 146-147 (under Barbus). According to L. S. 
Berg, H. barbus or schlegeli is to be called H. labeo {Cyprinus labeo Pallas), with maculatus (Bleeker) 
as a variety. 

Hypophthalmichthys Bleeker. In Gunther’s Catalogue this is considered typical of a distinct section 
or subfamily, Hypophthalmichthyina, or as we should now say, Hypophthalmichthyinae. I 
examined H. nobilis from Shanghai (Swinhoe; B. M.), but by an unfortunate accident the scale 
was lost when in the hands of the photographer. 

Ischikauia Jordan & Snyder. Zool. Anzeiger, xxxviii, p. 86, fig. 3. 

Labeo Cuvier. Proc. Biol. Soc. Wash., xxiii, p. 150-151, pi. m, fig. 2 (L. fimbriatus), fig. 7 (L. sene- 
galensis) ; Biol. Bulletin, vol. xx, pi. I. fig. 8 (L. sladoni). 

Leptobarbus Bleeker. L. hoevenii (Tinjar River, 200 miles from the sea, C. Hose; B. M.) is a fish with 
terminal mouth, having very large quadrate scales, my specimen 18 mm. long and 14 broad. The 
basal radii, about 14, are very delicate and irregular; lateral radii more or less developed; apical 
radii about 33; circuli evanescent apically. (PL xxxiv, fig. 15.) 





BULLETIN OF THE BUREAU OF FISHERIES. 


136 

Leptocypris Boulenger. Proc. Biol. Soc. Wash., xxin, p. 144. 

Leuciscus Cuvier, dace, chub, etc. Proc. Biol. Soc. Wash., xxn, p. 215-216 (including not only Leuciscus 
proper, but also Rutilus Rafinesque, Pigus Bonaparte, Cephalus Bonaparte, Idus Heckel, and Scar - 
dinius Bonaparte); Zool. Anzeiger, xxxvi, p. 479-480; Biol. Bulletin, xx, p. 371, pi. 1, fig. 7 ( L . 
illyricus), pi. 11, fig. 10 (L. rutilus), fig. 11 ( L.friesii ), fig. 12 (L. hakuensis), fig. 13 (L. jouyi). 
Leucogobio Gunther. I have L. mayedce (Jordan & Snyder) from Lake Biwa, Japan (Jordan & Snyder). 
The scales are much broader than long (length about 3X mm., breadth 5^3), but otherwise entirely 
of the type seen in Gobio, with the same radii, circuli, etc. 

Luciosoma Bleeker. I have three species from the British Museum. The scales are large and sub¬ 
quadrate; basal, lateral, and apical radii distinct, the lateral oblique, not or hardly at all directed 
toward the nucleus, except when the lower end is abruptly bent and turned inward; circuli very 
fine, but absent in the granular or striate apical field; laterobasal corners distinct. The species are 
separated thus: 

Nucleus central or nearly; scale 13 mm. long and 10 broad; about 10 apical radii; fish with dorsal 

fin very far back (W. Siam, Carl Bock). L. harmandi 

Nucleus conspicuously basad of middle. 1 

1. Scale reddish, n mm. long, io% broad; about 14 apical radii; fish with dorsal far back (Kapit, 

Rejang district, Sarawak, C. Hose). L. pellegrini Popta 

Scale white, 8 mm. long and 7 broad; about 14 apical radii; fish with row of large spots down 
side (Upper Baram River, C. Hose). L. trinema 

In scale characters the genus is very compact and except for the difference in the position of the 
nucleus the characters cited may not be specific. Scales of L. trinema are figured on plate 
xxxni, figure 7. 

There is a rather strong resemblance between the scales of Luciosoma and Leptobarbus hoevenii, but 
in Luciosoma the apical radii are spreading, fanlike, in the Leptobarbus they are parallel. 
Macrochirichthys; see Chela macrochir; Proc. Biol. Soc. Wash., xxm, p. 142. Fowler (1905) treats Macro- 
chirichthys as a distinct genus. 

Myloleucus Gunther. Cope published a genus of the same name at about the same time, but I believe 
the American genus has priority. 0 M. cethiops, from Kiu-Kiang (Styan; B. M.), has large scales, 
approximately circular, but with more or less evident laterobasal angles; length 12, breadth n mm.; 
nucleus central; area covered by skin unusually large, extending to nucleus, skin densely speckled 
with red-brown pigment; basal circuli quite dense; slight basal folds, but no radii; apical radii about 
a dozen, feeble; apical circuli strong, longitudinal, converging toward the middle, where they meet 
at very acute angles. A scale approaching the type of Cirrhina jullieni. 

Neobola Vinciguerra; see Engraulicypris. 

Opsariichthys Bleeker. Zool. Anzeiger, xxxvi, p. 252, fig. 1 (O. morrisonii ); xxxviii, p. 87. The species 
figured is now to be referred to Zacco. 

Oreinus McClelland. (PI. xxxiv, fig. 16.) A genus of mountain fishes with small scales, circular or 
broad-oval or ( grahami) sometimes sub trigonal, with nucleus central or nearly, circuli not very dense 
and rather widely spaced radii all around. They are therefore of the general type of Chrosomus and 
Phoxinus. The genus on scale characters is quite compact. Three species have been examined in 
the British Museum: 

O. grahami. Tongchuenfu, Yunnan (J. Graham). Scales 2 to 2% mm. diameter. 

O. plagiostomus (Heckel) Assam (F. Day). Scales about 1 by mm. 

O. richardsonii (Gray & Hardwicke) Nepal (B. H. Hodgson). Scales a little smaller than those of 
O. grahami. This genus is referred to the Schizothoracinae. 

Osteobrama Heckel. Day calls this genus Rohtee. Dr. G. A. Boulenger writes (litt., May, 1910): “ Rohtee 
Sykes and Osteobrama Heck, are synonyms. Both genera were established in the same year. I don’t 
know which has really priority.” I have four species from the British Museum. 


0 Dr. D. S. Jordan kindly informs me that Cope’s name has about a year’s priority. Myloleucus Gunther may be changed 
to Myloleucops n. n., our fish becoming Myloleucops aethiops. 







OBSERVATIONS ON FISH SCALES. 


137 


Scales elongate (8 mm. long, slightly over 3 yj broad), parallel sided, nucleus 2 mm. from anterior 
end; posterior end broadly and shallowly emarginate; circuli fine and dense; a single delicate 
radial line runs down the middle of the scale from the nucleus to the posterior margin, but 
otherwise there are no basal radii; apical field rugose, with very weak radii (Sittang River, 

E. W. Oates). O. microlepis 

Scales circular or nearly; nucleus nearly central; no basal radii, but the basal region more or less 

undulate... 1 

1. Scales broader than long; only feeble rudiments of basal radii; about 13 wavy apical radii (Sittang 

River, E. W. Oates).. O.alfrediana 

Scales larger (diameter 4^2 mm.); apical radii few, strong but very irregular and broken, wavy; a 

very deep-bodied fish (Sittang River, E. W. Oates). O.feae Vinciguerra 

Scales smaller (diameter about 3 mm.), apical field without circuli, but with weak and broken 
wavy radii (Sittang River, E. W. Oates). O. cotio (Hamilton Buchanan) 

The last three seem closely allied, but O. microlepis is very different and is probably not truly con¬ 
generic. In Gunther’s Catalogue Osteobrama stands next to Chanodichthys. The scale of Chanodich- 
thys, without basal radii, is in fact of a similar type, but much larger, with the numerous apical radii 
not distinctly wavy. 

Osteochilus Gunther. Zool. Anzeiger, xxxvi, p. 253, fig. 4 ( 0 . kahajanensis ). I have seven species 
from the British Museum, which are separable thus: 


Apical interradial area striate with longitudinal converging circuli. 1 

Apical interradial area evidently tuberculate, the circuli broken up. 2 


1. Scales about 7 mm. long and broad (Menam River, Siam; Royal Siamese Museum). . 0 . schlegelii 
Scales about 4 mm. long and 3-3X broad (Menam River, Siam; Royal Siamese Museum). 

O. melanopleurus 

2. Scales very large, 14 mm. long and 13 broad; apical radii wavy, basal radii very few and irregular 

(Baram River, Sarawak; C. Hose). O. hasseltii (Cuvier & Valenciennes) 

Scales smaller; apical radii essentially straight. 3 

3. Lateral radii few, reaching nuclear area; scales about 7 mm. long and 6 broad (Sittang River; 

E. W. Oates). O. neilli (Day) 

Lateral radii numerous, all or most failing to reach nuclear area.4 

4. Basal margin strongly trilobed (Deli, Sumatra; Moesch). O. waandersii 

Basal margin weakly undulate. 5 

5. Scale about 10 mm. long and 9 broad; skin pale with dark dots. (Baram district; C. Hose). 

O. kahajanensis 

Scale about 7 mm. long and 6 broad; skin brown (Tinjar River, 200 miles from sea; C. Hose). 

O. mttatus 

All are broadly rounded apically, essentially truncate basally, with evident laterobasal cor¬ 
ners; nucleus far toward the base (least so in O. neilli ); apical radii well developed, basal very 
poorly, feeble and irregular. The genus is a compact one on the scales, and the specific distinc¬ 
tions given are probably not all valid. (See also remarks under Cirrhina.) 

Paracheilognathus Bleeker. Proc. Biol. Soc. Wash., xxn, p. 157; Zool. Anzeiger, xxxvi, p. 477. Scales 
of P. rhombeus are about 2^ mm. long, 4^ broad; circuli not at all dense. 

Parapelecus Gunther. P. argenteus from Kiu-Kiang (Styan; B. M.) is a remarkable fish, with the scales 
inserted obliquely, and the lateral line abruptly bent. The scales are about 4 mm. long and 6K 
broad, covered with thin skin to the base. There are fine basal circuli, but no basal radii; in the 
apical field the circuli are wanting, but there are numerous irregular delicate radii. Thus the 
scale combines the shape of the Rhodeines with the sculpture of the Gobio group. Except for the 
larger size and covering of pinkish skin, the scales are extremely like the broader ones of Leucogobio 
mayedce. 

Phoxinellus Heckel. Proc. Biol. Soc. Wash., xxn, p. 216. The locality given as Oued el Mahd should 
be Oued (or Wed) el Mahdi; the printer took the i for a semicolon. The two lots of scales repre¬ 
sented Phoxinellus chaignoni (Vaillant) and P. callensis (Guichendt), which Boulenger now regards 
as distinct, though very closely allied. I fail to find any difference in the scales of the two. 
Phoxinus Rafinesque. Proc. Biol. Soc. Wash., xxn, p. 186 and p. 216; Zool. Anzeiger, xxxvi, p. 476. 
Pseudogobio Bleeker. Zool. Anzeiger, xxxvi, p. 478, fig- 1 ( P • esocinus Schlegel). 

Rasbora Bleeker. Proc. Biol. Soc. Wash., xxm, p. 144. 















138 


BULLETIN OF THE BUREAU OF FISHERIES. 


Rhinogobio Bleeker. Biol. Bulletin, xx, p. 371, pi. 11, fig. 9. Scale elongate, with broad truncate base. 
Rohita Valenciennes. R. lineata from the Sittang River (E. W. Oates; B. M.), has elongated scales, 
about 10 mm. long and 6>£ broad, the truncate base with a broad median lobe, bounded by the 
basal radii, which are two or three in number. Nucleus a short distance basad of center; gently 
curved delicate lateral radii; apical radii evanescent or extremely feeble; skin-covered area strongly 
tuberculate. The shape of the scale is very like that of Labeo fimbriatus. (PI. xxxm, fig. 9.) 
Saurogobio Bleeker. Zool. Anzeiger, xxxvi, p. 478. Scales elongated; those of 5 . dumerilii much 
like those of Rhinogobio typus; both species collected by Styan at Kiu-Kiang. 

Scaphiodon Heckel. Scales broader than long, with small subbasal nucleus; apical radii numerous, 
but no basal ones; interradial area tuberculate. I have two species from the British Museum, 
very much alike, but separable as follows: 

Base with a very prominent rounded lobe; laterobasal corners very distinct; skin pallid, speckled 

with light brown (Sind; F. Day)... 5 . watsoni Day 

Basal margin convex, but not lobed; laterobasal comers indistinct; skin brown, speckled with 
darker (Muscat, Arabia; A. S. G. Jayakar). 5 . muscatensis 

Except for the broader scales and denser sculpture there is an evident resemblance to Capoeta. 
This resemblance doubtless extends to other than scale characters, for Cuvier and Valenciennes 
included species of Scaphiodon in Capoeta. S. muscatensis is figured on plate xxxm, figure 10. 
Scaphiodontichthys Vinciguerra. My two scales of 5 . burmanicus, from Mount Mooleyit (Fea; B. M.), 
are both latinucleate; the scale is broader than long (about 7 by 8 mm.), considerably larger than 
that of Scaphiodon, with numerous apical radii but no basal; the basal margin is convex, without 
any lobe, and without laterobasal comers. The scale is structurally close to that of Scaphiodon. 
Schizopygopsis Steindachner. I microscopically examined the skin of 5 . stoliczkae (Seistan, Helmund 
River, Col. McMahon; B. M.) and 5 . younghusbandi (Lhasa, Tibet, H. J. Walton; B. M.), but 
found no scales. The skin in >S. younghusbandi is clear, profusely dotted with lichenoid spots of 
dark brown pigment. 

Schizothorax Heckel. Biol. Bulletin, xx, pi. iv, fig. 22 (S. biddulphii ); Zool. Anzeiger, xxxvi, p. 476. 
In S. intermedius (Kashgar; B. M.) the scales are elongate as in S. biddulphii, and the sculpture is 
in all respects the same, except that it is less dense. (PI. xxxm, fig. 11.) 

Semiplotus Bleeker. In Semiplotus semiplotus (Cyprinus semiplotus McClelland, Semiplotus mac- 
clellandi Bleeker) from Assam (F. Day; B. M.) the scales are quite large, reddish, broader than long 
(length 13, breadth 15 mm.); nucleus a short distance below the middle; basal radii 3 or 4, feeble; 
slender curved lateral radii; apical radii very numerous, wavy; apical field coarsely tuberculate. 
The scale is of entirely the same general type as that of Barynotus luteus, but shorter, with much 
less prominent laterobasal comers, and fewer and feebler basal radii. The color is the same in 
both, and the differential characters cited are doubtless more or less variable. (PI. xxxm, fig. 12.) 
Squaliobarbus Gunther. Biol. Bulletin, xx, p. 371, pi. 1, fig. 6 (S. curriculus). 

Tinea Cuvier. Zool. Anzeiger, xxxvi, p. 476; Biol. Bulletin, xx, p. 373, pi. iv, fig. 21. 

Tylognathus Heckel. Day treats this as a synonom of Labeo. I have five species from the British 
Museum. They agree in having numerous apical radii and the apical field tuberculate. So far 
as the material goes, they appear to be separable as follows: 

The subquadrate scale broader than long (about 7 mm. long and 8 broad); laterobasal comers very 
prominent; basal radii very numerous, but fine and irregular; apical radii strong, more or less 

wavy, the interradial tubercles very strong. T. (“ Lobocheilus") lehat 

The subquadrate scale a little longer than broad (about 8 mm. long and 7^ broad); general charac¬ 
ters like the last, but apical radii scarcely wavy, and interradial tubercles weaker (Pata R.; 

C. Hose). T. hispidus 

Scale conspicuously longer than broad, parallel-sided, shape like that of Labeo fimbriatus . 1 

1. Scale about 12 mm. long and 8 broad (Bowany R.; F. Day). T. ariza (Buchanan) 

Scale about 7 mm. long and 4 broad, but fish not adult (Madras; F. Day). ,T. boga (Buchanan) 
Scale about 5% mm. long and 3^ broad (Poona; Lieut. Col. Playfair). T. striolatus 

The following Asiatic Labeo have scales of the Tylognathus type, or approximating it; L. sindensis, 
L.falcatus, L. bicolor, L. sladoni, L. ricnorhynchus, L. kontius (nearly shape and size of T. ariza, but less 









OBSERVATIONS ON FISH SCALES. 


139 

elongate), L. leschenaultii (looks like T. ariza, but differs by strong basal radii, which are entirely absent 
m T. ariza), L. bata (quite like T. ariza, with no basal radii), L. pangusia, L. nigripinnis, L. kawrus, 
L. microphthalmus . Several others approach the same type quite closely, and it is evident that so far 
as the scales go, Tylognathus can not be separated from Labeo. 

Varicorhinus Ruppell. Proc. Biol. Soc. Wash., xxiii, p. 148. 

Xenocypris Gunther. Zool. Anzeiger, xxxvi, p. 253, fig. 5 ( X . argentea). I have two species from the 
British Museum, both having pale subcircular scales. 

Scale about 5X mm. long and 5 Abroad; laterobasal comers rounded; no basal radii; circuli in inter- 
radial (apical) region strong, transverse; nucleus almost central (Kiu-Kiang; Styan). 

_ t X. microlepis 

Scale about 3% mm. long and 3 % broad; laterobasal comers more evident; no basal radii; apical 
radii 7 or 8, the interradial circuli transverse, strong, widely spaced; nucleus far basad of 
middle (mountain streams near Kiu-Kiang; Styan). X. argentea Gunther 

In the apical field there is a strong resemblance to Chondrostoma, but that genus has well- 
developed basal radii. See also Zool. Anzeiger, xxxvm, p. 86. 

Zacco Jordan & Evermann. Zool. Anzeiger, xxxvm, p. 86, fig. 4. 

CATOSTOMIDE. Suckers and buffalo-fishes. 

The scales of the Catostomidae are usually quite large, and resemble those of the Old World Cyprinidae 
in most respects. For figures see Proceedings Biological Society of Washington, volume xxn, page 158, 
figure 2 ( Catostomus griseus ; the figure is printed upside down); Biological Bulletin, volume xx, plate 1, 
figure 3 ( Moxostoma aureolum), and figure 4 (Pantosteus santa-ance). In every case the basal radii are 
well developed. The scales of Moxostoma cervinum Cope, showing two types, one reticulated, are 
described in Science, July 28, 1911, page 126. 

Subfamily ICTIOBINE. Buffalo-fishes. 

In the carp sucker, Carpiodes velifer (Rafinesque), the scales from just below the front of the dorsal 
fin are broader than long, but those from between posterior end of dorsal and lateral line are longer than 
broad. The scales studied are from a fish about 4 pi inches long, from the Wabash River, Indiana 
(Bureau of Fisheries). Apical margin broadly rounded; laterobasal angles distinct; base rounded, 
forming a single broad lobe, between which and the laterobasal angles the margin is concave; circuli 
very distinct, in the apical field only about half as closely set as laterally and basally; apical radii few, 
usually three, one median, and a curved one on each side, but sometimes five are present; basal radii 
numerous, about 30, or more counting imperfect ones, close together; nucleus central or almost. Latinu- 
cleate scales are coarsely and irregularly reticulate in the middle. Compared with the Catostomine 
series, this falls with Catostomus commersonii, from which it is at once separated by the character of 
the apical radii. 

Subfamily CATOSTOMINE. Suckers. 

Scales very small; oval, oblong, or subcircular, without laterobasal comers. 1 

Scales larger, often very large, with evident laterobasal comers.. 4 

1. Radii all around; nucleus more or less apicad of middle (Boulder County, Colo.). 

Catostomus griseus (Girard) 

Radii apical and basal, the lateral basal ones usually not pointing to the nucleus, but when 
complete strongly crooked above, the bent basal end then pointing to the nuelcus; nucleus 
central or basad of center. 2 

2. Nucleus nearly central, or moderately basad of middle. 3 

Nucleus far basad of middle of the very small scales (Russian River, Cal.; Stanford University. 

Catostomus occidentalis Ayres 

3. Scales often broader than long, but variable (Oregon).C. macrocheilus Girard 

Scales longer than broad, but little different from the last (California). .C. humboldtianus Snyder 
Scales closely resembling the last, but with lateral circuli more developed, so as to approach 

C. griseus, except for the more basad nucleus (California). Pantosteus santa-ance Snyder 

(The tubercles in the upper lip are much more numerous in the Pantosteus than in 
Catostomus macrocheilus.) 








T40 


bulletin of the bureau of fisheries. 


6 . 


8 . 


Lateral and apical (interradial) circuli about equally far apart, strictly transverse. 5 

Apical circuli conspicuously more widely spaced than lateral. 6 

Scale subcircular, about 4J2 mm. diameter, with about 4 to 6 apical, and 17 to 20 basal (no lateral) 
radii (Little South Fork, Cumberland River, Ky.; P. H. Kirsch), 

Lagochila lacera Jordan & Brayton 
Scale smaller, rather more quadrate, with very prominent laterobasal angles; radii very strong, 
apical 4 to 6, basal 6 to 8 (Cherokee, Iowa; S. E. Meek ) .Placopharynx duquesnii (Le Sueur) 
Basal radii very numerous, 12 in young scales, up to 20 or more in adult; center reticulated in 

latinucleate scales .. Catostomus commersonii (Lac6p£de), including C. teres Mitchill 

Basal radii less numerous. 7 

Basal radii more than 12; scale hardly differing from C. commersonii, but interradial circuli 

more arched. Erimyzon sucetta (Lacepede) 

Basal radii about 7 to 9 in normal scales. 8 

With many incomplete apical radii. Moxostoma cervinum (Cope) 

With at most one or two incomplete apical radii. Minytrema melanops (Rafinesque) 


The scales of several of the above, but especially those of Lagochila, are quite of the type of Chon- 
drostoma. It is evident that the scales of the American Catostomidae can be practically matched among 
the Palaearctic and Oriental Cyprinidae, excepting only the western small-scaled group of Pantosteus and 
Catostomus griseus, occidentalis, etc. Even this exception is doubtful, for these smaller scales are cer¬ 
tainly extremely like those of Oreinus, from Yunnan, Nepal, Assam, etc. It thus seems entirely impos¬ 
sible to find a scale character separating the Catostomidae from the Old World Cyprinidae. Decactylus 
Rafinesque, type Decactylus commersonii (Lac&pede), or if Lacepede’s fish is considered dubious, Decac¬ 
tylus teres (Mitchill), seems to be a valid genus, but Catostomus occidentalis, macrocheihis, etc., must be 
excluded from it. 

COBITIRF. Loaches. 


Subfamily COBITIN^E. 

The scales of this subfamily have been discussed in Proceedings of the Biological Society of Wash¬ 
ington, volume xxn, pages 205-206. The following genera are available for examination: 

Cobitis Linnaeus. T. c., p. 206 (C. tcenia). 

Misgurnus Lacepede. T. c., p. 206 ( M.fossilis, M. anguillicaudatus ). 

Somileptes (Swainson) Bleeker. T. c., p. 206 ( Cobitis gongota). 

Lepidocephalichthys Bleeker. T. c., p. 206 (L. berdmorei and L. guntea). 

Acanthopsis Van Hasselt. A. chcerorhynchus (Bleeker) from Meetam, Tenasserim (Fea; B. M.) has 
scales which are much broader than long, with radii all around; transverse diameter less than half a 
millimeter. The scales are of the same general type as those of Cobitis tcenia, and entirely different 
from the elongated scales of Somileptes and Lepidocephalichthys. 


Subfamily HOMALOPTERINAL East Indian loaches. 

For Gastromyzon and Homaloptera (pi. xxxiv, fig. 17) see Proceedings Biological Society of Wash¬ 
ington, volume xxn, pages 206-207. 

KNERIIDJJ. 

Proceedings Biological Society of Washington, volume xxiii, page 113 ; Biological Bulletin, volume 
xx, plate v, figure 31. ( Kneria cameronensis Boulenger). This family falls here in Jordan’s list, but 

in his two-volume work no justification for this position is found. Boulenger, having examined the 
skeleton of K. cameronensis, places the family between Phractolaemidae and Cromeriidse. Regan (1911) 
places it near to Chanidae, or milk fishes. It is an isolated type, and its scales are very peculiar. 

Suborder GYMNOTI. Electric eels. 

• 

Dr. Max Ellis has in preparation a detailed paper on the scales of this group. He has very kindly 
allowed me to examine his series of slides in order to state the principal characters. Greatly to my sur¬ 
prise I find the scales to be quite different from those of the characinids known to me, but very similar 










OBSERVATIONS ON FISH SCALES. 


141 

indeed to those of such cobitids as Misgurnus and Lepidocephalichthys . They may also be compared 
with the small-scaled catostomids, as Pantosteus, or in Cyprinidse with Oreinus. This general type of 
scale, with radii all around and a sort of latticework pattern, is, I believe, really primitive, with char¬ 
acters not very distantly approaching those of the amphibian Ichthyophis. It appears, therefore, that 
the gymnotids are not “degraded characinids” (Boulenger), but rather specialized pre-characinids. 
The fully developed radial pattern is found in the small-scaled gymnotids, the scale being nearly cir¬ 
cular ( Gymnotus carapo ), or elongated ( Sternopygus macrurus), or transversely oval ( Hypopomus artedi). 
In Eigenmannia virescens more than half the scale is without radii, and if they all disappeared we should 
have a scale not very unlike that of the characinid Serrasalmo. 

In the larger scales of Porotergus and Sternarchus the radii are very fine and the basal ones converge 
to the middle line, curiously simulating the condition found in some Gadidae, as Urophycis. 

Order SCYPHOPHORI. 

For the Mormyridae (including Gymnarchidae) see Smithsonian Miscellaneous Collections, volume 
56, no. 3. In Jordan’s list the Haplochitonidae andGalaxiidae appear as Scyphophori, but this reference 
is opposed to the treatment in the earlier part of the book, and according to Regan (1911) they are 
salmonoids. 

Order HAPLOMI. 

ESOCIDAJ. Pikes. 

Esox (or Lucius) lucius from Toledo, Ohio (Rutter), has oblong scales about 3.5 mm. long and 
slightly over 2.5 wide; nucleus anterior to the middle; no apical radii, but two or three very strong 
basal radii or plicae, ending between the large lobes of the basal margin. The circuli are dense, the apical 
ones distinct and transverse, with no approach whatever to any ctenoid structure. The base of the 
scale is nearly as in Synodus. (PI. xxxv, fig. 20.) 

UMBRIDi®. Mud Minnows. 

Umbra limi (Kirtland) from Milwaukee County, Wis. (Graenicher), has peculiar subquadrate or 
oblong scales, the largest about 3 mm. long, wholly unlike those of Esox. There are no radii, nor is the 
basal margin at all lobed. The very coarse circuli are essentially longitudinal, extending from one end 
of the scale to the other, but the innermost slant toward the middle line, meeting those of the opposite 
side at an extremely acute angle. In the largest scales the apical circuli are not angled in the middle, 
but normally arched, becoming transverse in the middle; the basal circuli in the same scales converge 
to two or three points, producing a transversely zigzag appearance. In Kneria the system of circuli is 
very much the same, though differing in detail. Much more noteworthy and surprising is the great 
resemblance in structure to the scales of Urophycis regius. So far as the scales go, Umbra and Urophycis 
might be imagined to belong to closely allied genera. Dr. Gill (Smiths. Misc. Coll., vol. 45, p. 297) 
has given a rather unsatisfactory figure of an Umbra scale. 

PCECIILIDjE. Killifishes. (PI. xxxv, fig. 21, 22; pi. xxxvi, fig. 23.) 

Scales broad, more or less semicircular, cycloid, with the nucleus apicad of middle and strong basal 
radii. No apical radii; circuli not, or not very, dense. Tilapia (Cichlidae) has the same sort of scale, 
thus quite different from that of Pomacentridae ( Eupomacentrus and Abudefduf examined), which is 
ctenoid, of the ordinary Acanthopterygian type.® Compared with Esox or Lucius the Pceciliid scale 
differs by its broad form (the scale of Lucius is longer than broad), numerous basal radii (two or three in 

a Many Cichlidae have ctenoid scales, and no doubt Tilapia is secondarily, not primitively, cycloid; a parallel development 
to that of the Embioticidae. In fact, it is not quite correct to say that Tilapia is cycloid, since extremely minute marginal teeth 
can be detected with the compound microscope. 



142 


bulletin of the bureau of fisheries. 


Lucius ), and much less dense circuli. On the other hand, the scale of Dallia pectoralis does not essen¬ 
tially differ from the smaller pceciliid scales, though the sculpture is less regular. Latinucleate scales 
are common in the pceciliid material examined. 

The following rather unsatisfactory key is based on normal (not latinucleate) scales: 


Scales larger, more than 3 mm. across. 1 

Scales smaller, less than 3 mm. across.. • • • 4 


1. Apicolateral outline a regular even curve, or without angles; nucleus a short distance apicad of 

middle; basal radii about 17, only about the 10 midmost complete. 

Cyprinodon carpio Gunther. Tarpon Springs, Fla. (Evermann & Kendall). 
Apicolateral outline evidently bent or angled, the apical margin thus separated from the lateral.. 2 

2. Nucleus less than a third of length of scale from apex; apicolateral angles pronounced, but apical 

margin convex; basal radii about 13 to 16. 

Gambusia puncticulata Poey. San Antonio, Pinar del Rio, Cuba (Eigenmann & Riddle) 
Nucleus more than a third of length of scale from apex. 3 

3. Scale larger, very broad (lat. pr. 6 mm.), apical margin hardly elevated. 

Fundulus heteroclitus (Linnaeus), Woods Hole, Mass. 
Scale smaller, not so broad (lat. pr. 4 mm.) apical margin more elevated. 

Mollienisia latipinna Le Sueur, Gordon’s Pass, Fla. (Henshall). 
Differing from the above two in having the scale longer than broad. 

Fundulus majalis (Walbaum). 

4. Nucleus far above middle of scale; basal radii about 10 or n. 

Poecilia butleri; Jordan; fish about 40 mm. long; SalinaCruz, Mexico (C. C. Deam). 
Nucleus about middle of scale or even below. 5 

5. Scale subquadrate, with more or less evident anterolateral angles. 

Fundulus diaphanus (LeSueur), Osterville, Mass. 
Scale broad, not subquadrate, without anterobasal angles. 6 

6. Scale less than 1% mm. diameter. Lucania parva (Baird & Girard), Woods Hole, Mass. 

Scale more than mm. diameter. 

Gambusia affinis (Baird & Girard), Myakka River, Florida (J. A. Henshall). 

Dr. Max Ellis has kindly allowed me to examine scales of Anableps anableps (Linnaeus) the four¬ 
eyed fish, and A. microlepis Garman, which he collected at Georgetown, British Guiana. They are 
quite large, those of A. anableps much broader than long, with a width of about 8 mm., those of 
A. microlepis smaller, and not so broad. In all respects they are quite typical pceciliid scales, much 
like those of Cyprinodon, but with considerably denser lateral circuli. 


Order XENOMI. 

DALLIIDAJ. Alaska blackfish. 

Dallia pectoralis Bean, from Nushagak, Alaska (Albatross collections) has small scales about mm. 
diameter, with coarse circuli and numerous (about 15) basal radii, the basal margin finely scalloped. 
There is nothing in these scales which might not be expected in the Poeciliidae. Regan has recently 
proposed to include the Esocidae, Umbridae, and Dalliidae in Haplomi and to recognize a new order, 
Microcyprini, for the Poeciliidae and Amblyopsidae. So far as the scales go, the following arrangement 
would seem natural. 

1. Umbridae. 

2.A. Esocidae. 

B.a. Dalliidae. 

b. Poeciliidae, 

the last showing a close approach to the acanthopterygian type. 










OBSERVATIONS ON FISH SCALES. 


143 


Order ACANTHOPTERI. Spiny-rayed fishes. 


THE ACANTHOPTERYGIAN TYPE OF SCALE. 

The serranid Centropristes striatus (Linnaeus), the black sea bass, from Woods Hole, Mass., may 
be taken as a type for the definition of the acanthopterygian scale. This scale is more or less quadrate, 
with the nucleus subapical, the basal circuli fine and transverse, the basal radii strong, spreading out 
like a fan, and the apical area covered with fine dentiform structures which can 
be counted in rows obliquely or transversely, and on the margin form a series of 
fine teeth. The Centropristes scale described is atypical in one respect—the 
marginal teeth are truncate instead of pointed. The toothed or ctenoid feature 
appears to be derived from the longitudinal apical circuli which become modi¬ 
fied and segmented, the terminal segments especially taking the form of teeth. 

It is this segmentated arrangement which gives the apical area in acanthop- 
terygians its special character, resembling very much the arrangement of bracts 
in the heads of some composite flowers. In the poeciliid scale we have a 
structure resembling much that of the acanthopterygians, but the ctenoid char¬ 
acter wholly undeveloped; in some cichlids we attain a superficially similar 
condition, the ctenoid character having been lost. 

At first sight the scales of the various acanthopterygian families Haemulidae, 

Lobotidae, Serranidae, Lutianidae, Percidae, Centrarchidae, Anabantidae, Sciaenidae, 

Mullidae, Polynemidae, and Mugilidae appear so much alike that classification 
seems extremely difficult. There are, however, some good distinctions visible 
on close comparison and brought out more or less in the following table. This does not apply to 
latinucleate or lateral line scales. 



A 

if) a \'i} 

\ts V v 


Fig. 8. —Centropristes stri¬ 
atus (Serranidae). Cte¬ 
noid structures. Bureau 
of Fisheries. 


Basal margin broadly emarginate in middle, the basal radii (about 4 or 6 distinct) nearly parallel, 
converging toward the margin; teeth of apical margin very small, not different from the sub¬ 
marginal structures. Mugil curema Cuvier & Valenciennes (Mugilidae) 

Basal radii spreading......... 1 

1. Middle of basal margin deeply emarginate; radii one in the middle, and usually three (closer 

together than the innermost to the middle one) on each side, not deeply impressed; apical 
modified area reaching nearly to nucleus; apical marginal teeth very small, sharp; sub- 
apical pattern composed of elements resembling phalanges, but grooved or bicarinate.® 

Polydactylies octonemus Girard (Polynemidae) 
Basal margin deeply lobed between the five of six widely and often irregularly spaced basal radii; 
large scales with extremely fine circuli; modified marginal area not approaching nucleus; 
marginal teeth sharp; submarginal elements phalangiform, flattened, looking like bricks 
placed on end, without grooves or keels, though some of the basal ones may have broken ver¬ 
miform markings. Surmullets (Mullidae). 2 

Not like the above (in Perea the basal margin is strongly lobed, but then the basal radii are regular 
and very deeply impressed, and the apical region is differentiated into two parts). 4 

2. Subapical marginal elements longer, many about four times as long as broad. 

Mullus auratus Jordan & Gilbert, Woods Hole, Mass. 

Subapical marginal elements shorter, none about four times as long as broad.3 

, Elements of apical area in 5 or 6 transverse rows (only two in latinucleate scales). 

Upeneus dentatus Gill. Clarion Island (Albatross) 
Elements of apical area in 8 or 9 transverse rows. 

Mulloides samoensis Gunther. Honolulu, Hawaii (Jordan & Evermann) 
4 Apical area beset with linear, spine-like structures (the marginal teeth not differing), the lateral 
ones often continuous at base with the circuli; apical circuli very widely spaced, meeting 
at about a right angle above nucleus; basal radii about 15 (Anabantidae). 

Anabas scandens Linnaeus. Lake Buhi, Philippine Islands 


Apical area not thus.....•.• • •.•• 5 

r Scales conspicuously longer than broad; margin with about 7 or 8 prominent teeth or projections, 
to the ends of which the basal framework of the scale is carried; apical area with much 
reddish brown pigment; scale suggestive of Achirus, but the subapical structure different. 

Epinephelus niveatus (Cuvier & Valenciennes). Katama Bay, Mass. (Serranidae) 
Apical margin with many teeth. 6 


In Mugil these structures are dentiform, like pointed scales, thus very different. 

















144 


bulletin of the bureau of fisheries. 


6 . 


7- 


8 . 


13 


14- 


Marginal teeth truncate, often (except in Micropogon ) broader at end than in middle. 7 

Marginal teeth sharply or rather obtusely pointed..... 12 

Circuli above the nucleus broad and sublongitudinal, so that the nucleus and adjacent circuli 

suggest a section of an onion.. 8 

Circuli above the nucleus transverse (concentric) or (in Orthopristis) evanescent. 10 

Scales much larger (about 8 mm. long and broad); elements of apical area with the median 
oblique rows about 12 or 13, but the inner ones poorly developed; basal radii about 9 or 10. 

Centropistes striatus (Linnaeus). Woods Hole, Mass. (Serranidae) 
Scales smaller (less than 4 mm. long), longer than broad; inner elements of apical area distinct 

(Serranidae). 9 

9. Scales 3 to nearly 4 mm. long. 

Paralabrax maculatofasciatus (Steindachner). Guaymas, Mexico (Albatross) 
Scales ipi to 1^3 mm. long. .. .Paralabrax clathratus (Girard). San Diego Bay, Cal. (Albatross) 

10. Circuli above the nucleus lost, the surface finely roughened. 

Orthopristis chalceus (Gunther). Guaymas or Clarion Island (Albatross). (Haemulidae) 
Circuli above the nucleus distinct. n 

11. Scale larger, up to over 10 mm. broad; elements of apical area in middle about 16 in a longi¬ 

tudinal series. Micropogon undulatus (Linnaeus). (Sciaenidae) 

Scale smaller; elements of apical area in middle 8 or less in a longitudinal series. 

Leiostomus xanthurus Lacepede. Florida. (Sciaenidae) 

12. Apical teeth very short, for the most part hardly so long as their distance apart. 13 

Apical teeth well developed. 14 

Apical teeth more or less bifid at tip; sculpture of apical area strong. 

Morone americana (Gmelin), fish nearly 8 inches long. (Serranidae) 
Apical teeth not bifid; sculpture of apical area weak. 

Micropterus salmoides (Lacepede). Falmouth, Mass. (Centrarchidae) 

Scales large, colorless, very broad (a well developed one about 11 mm. broad and 8 long), 
often inequilateral; basal radii very numerous (about 40) and close together; elements of 
apical area longitudinally ridged or keeled. 

Cynoscion regalis (Bloch & Schneider). Woods Hole, Mass. (Sciaenidae) 
Scales very large, quadrate, equilateral (a well developed one about 16 mm. long and 15^ 
broad), orange-fulvous; basal radii very numerous (about 37, but many only in the 
peripheral area); circuli puncticulate; submarginal elements of apical area much longer 

than broad. Lobotes surinamensis (Bloch). (Lobotidae) 

Scales smaller and otherwise different; many very small. 15 

Base of scale very deeply crenate, many of the lobes as long as broad; basal radii 5 or 6; apical 
area with a marginal band in which the elements are very distinct, but mesad of this they 
are indistinct, the transition abrupt. 

Perea flavescens (Mitchill). Falmouth, Mass. (Percidae) 

Base of scale not thus deeply crenate. 16 

16. Scales larger, fully 5 mm. long and broad; basal radii very numerous (about 28-32) and close 
together; basal circuli puncticulate. 

Roccus lineatus (Bloch). Woods Hole, Mass. (Serranidae) 

Scale much smaller; basal radii less than 20. 17 

Basal radii about 18. 

Hypohomus spilotus (Gilbert). Hector Creek, Kentucky. (Woolman). (Percidae) 

Basal radii usually less than 10 (9 to 11 in Neomcenis) . 18 

Submarginal elements of apical area much longer than broad. 19 

Submarginal elements of apical area mostly or all broader than long. 20 

Lateral circuli strongly curving inward above. 

Morone americana (Gmelin), fish 3 inches long. (Serranidae) 
Lateral circuli (except the innermost) hardly curving inward above. 

Neomcenis analis (Cuvier & Valenciennes). Katama Bay, Mass. (Lutianidae) 

20. Scales very small; apical teeth broad at base, rapidly tapering to very slender sharp points; 

basal radii 6 to 9. Boleosoma nigrum (Rafinesque). Osterville, Mass. (Percidae) 

Apical teeth conical, more regularly tapering.. 21 

21. Lateral circuli (except the innermost) directed obliquely outward above, so that if they were 

continued in a straight line below until they met, they would form a broad V; basal radii 

7 to 8. Brachydeuterus leuciscus (Gunther). San Juan Lagoon, 

Rio Ahoma, Mexico (Albatross). (Haemulidae) 
Lateral circuli (except the innermost) directed upward above. 22 

22. Submarginal elements of apical area appearing distinctly concave below (helmet-shaped); 

basal radii 8. 8 

Hcemulon steindachneri (Jordan & Gilbert). Gulf of California (Albatross). (Haemulidae) 


i5 


17 


18 . 


19 























OBSERVATIONS ON FISH SCALES. 


H5 

Submarginal elements of apical area not appearing concave below. 23 

23. Submarginal elements of apical area hat-shaped. 

Cottogaster shumardi (Girard). Wabash River, Ind. (B. W. Evermann). (Percidae) 
Submarginal elements of apical area quadrate. 

Menticirrhus saxatilis (Bloch & Schneider). Woods Hole, Mass. (Sciaenidse) 

Suborder Synentognath. 

BELONIDAJ. Marine gars. 

The houndfish, Tylosurus acus (Lacepede) has irregular elongate (broad) scales with conspicuous 
concentric circuli, but no radii whatever. They thus recall the scales of Salmonidae. 

EXOC(ETIDiE. Flying-fishes. 

Cypsilurus heterurus (Rafinesque) has large broad thin scales, about 10 mm. broad and 8 long; 
nucleus a short distance below middle; circuli strong, concentric, in some scales much more widely 
spaced laterally, and then often angled; margin wholly cycloid; about 4 or 5 strong basal radii (more in 
latinucleate scales), none apical. Except for the presence of radii, this is very similar to Tylosurus. 
It seems also to lead toward the scombrid type. 

HEMIRHAMPHID^. Halfbeaks. 

Hyporhamphus unifasciatus (Ranzani), from Woods Hole, Mass., has very broad scales, about 5 mm. 
long and 8, or slightly over, broad; apical margin broadly rounded; laterobasal comers rounded but 
evident; middle of base with a broad median lobe, which may be bilobed; basal radii two or three, 
widely diverging; nucleus near middle, but indistinct; apical field entirely covered with very fine 
transverse circuli, except a slender sculptureless submarginal band; basal field with transverse more 
widely spaced circuli, bending upwards and still more widely spaced in the lateral fields, and ulti¬ 
mately, when not reaching the margin, forming acute angles with the adjacent circuli of the apical 
field. The transverse dense apical circuli remind one of Xystazma (Gerridae), but in Xystczma there 
is no sign of lateral angulation, and the apical marginal region is entirely different. 

The scale of Hyporhamphus is evidently a further development, much more extreme, of the type 
of Cypsilurus. It also seems to point clearly in the direction of the scombrids. 

SCOMBRESOCIDAE. Sauries. 

The billfish, Scomhresox saurus (Walbaum) represents a still more extreme development along the 
lines of Hyporhamphus. The thin scale is about 5 mm. long and 8 broad, without angles or radii. The 
circuli are everywhere completely transverse, denser on the apical than the basal half, the two halves 
separated in some cases by more or less of an interval about the middle. At each extreme side is a 
thin zone, sculptureless except for a few irregular lines. The scales are of the same general type as 
those of the Scombridse and Cheilodipteridse. 

So far as seen, the synentognathous families may be separated thus: 


Apical and basal circuli about the same. 1 

Apical circuli transverse, denser than basal. 2 

1. Radii absent.Belonidae 

Basal radii strong.Exoccetidse 

2. Without radii.Scombresocidse 

With radii.Hemirhamphidae 


If doubt should arise owing to the apical circuli of Scombresocidae not being much denser than the 
basal, the family will still be easily recognized by the completely transverse character of the circuli, 
so that the effect of lateral angulation is lost. Dr. Jordan states that Regan (1911) recognizes an order 
Synentognathi, with one suborder for the belonids and scombresocids, and another for the hemirham- 
phids and exocoetids. The scale characters would not have suggested this arrangement. 

89970 0 —13-3 









144 


bulletin of the bureau of fisheries. 


6. Marginal teeth truncate, often (except in Micropogon) broader at end than in middle. 7 

Marginal teeth sharply or rather obtusely pointed.... . 12 

7. Circuli above the nucleus broad and sublongitudinal, so that the nucleus and adjacent circuli 

suggest a section of an onion.. 8 

Circuli above the nucleus transverse (concentric) or (in Orthopristis) evanescent. 10 

8. Scales much larger (about 8 mm. long and broad); elements of apical area with the median 

oblique rows about 12 or 13, but the inner ones poorly developed; basal radii about 9 or 10. 

Centropistes striatus (Linnaeus). Woods Hole, Mass. (Serranidae) 
Scales smaller (less than 4 mm. long), longer than broad; inner elements of apical area distinct 
(Serranidae). 9 

9. Scales 3 to nearly 4 mm. long. 

Paralabrax maculatofasciatus (Steindachner). Guaymas, Mexico (Albatross) 
Scales ipi to 1^3 mm. long. .. .Paralabrax clathratus (Girard). San Diego Bay, Cal. (Albatross) 

10. Circuli above the nucleus lost, the surface finely roughened. 

Orthopristis chalceus (Gunther). Guaymas or Clarion Island (Albatross). (Haemulidae) 
Circuli above the nucleus distinct. 11 

11. Scale larger, up to over 10 mm. broad; elements of apical area in middle about 16 in a longi¬ 

tudinal series. Micropogon undulatus (Linnaeus). (Sciaenidae) 

Scale smaller; elements of apical area in middle 8 or less in a longitudinal series. 

Leiostomus xanthurus Lacepede. Florida. (Sciaenidae) 

12. Apical teeth very short, for the most part hardly so long as their distance apart. 13 

Apical teeth well developed. 14 

13. Apical teeth more or less bifid at tip; sculpture of apical area strong. 

Morone americana (Gmelin), fish nearly 8 inches long. (Serranidae) 
Apical teeth not bifid; sculpture of apical area weak. 

Micropterus salmoides (Lacepede). Falmouth, Mass. (Centrarchidae) 

14. Scales large, colorless, very broad (a well developed one about 11 mm. broad and 8 long), 

often inequilateral; basal radii very numerous (about 40) and close together; elements of 
apical area longitudinally ridged or keeled. 

Cyno scion regalis (Bloch & Schneider). Woods Hole, Mass. (Sciaenidae) 
Scales very large, quadrate, equilateral (a well developed one about 16 mm. long and 15% 
broad), orange-fulvous; basal radii very numerous (about 37, but many only in the 
peripheral area); circuli puncticulate; submarginal elements of apical area much longer 

than broad. Lobotes surinamensis (Bloch). (Lobotidae) 

Scales smaller and otherwise different; many very small. 15 

15. Base of scale very deeply crenate, many of the lobes as long as broad; basal radii 5 or 6; apical 

area with a marginal band in which the elements are very distinct, but mesad of this they 
are indistinct, the transition abrupt.' 

Perea flavescens (Mitchill). Falmouth, Mass. (Percidae) 
Base of scale not thus deeply crenate. 16 

16. Scales larger, fully 5 mm. long and broad; basal radii very numerous (about 28-32) and close 

together; basal circuli puncticulate. 

Roccus lineatus (Bloch). Woods Hole, Mass. (Serranidae) 
Scale much smaller; basal radii less than 20. 17 

17. Basal radii about 18. 

Hypohomus spilotus (Gilbert). Hector Creek, Kentucky. (Woolman). (Percidae) 
Basal radii usually less than 10 (9 to 11 in Neomcenis) . 18 

18. Submarginal elements of apical area much longer than broad. 19 

Submarginal elements of apical area mostly or all broader than long. 20 

19. Lateral circuli strongly curving inward above. 

Morone americana (Gmelin), fish 3 inches long. (Serranidae) 
Lateral circuli (except the innermost) hardly curving inward above. 

Neomcenis analis (Cuvier & Valenciennes). Katama Bay, Mass. (Lutianidae) 

20. Scales very small; apical teeth broad at base, rapidly tapering to very slender sharp points; 

basal radii 6 to 9. Boleosoma nigrum (Rafinesque). Osterville, Mass. (Percidae) 

Apical teeth conical, more regularly tapering.. 21 

21. Lateral circuli (except the innermost) directed obliquely outward above, so that if they were 

continued in a straight line below until they met, they would form a broad V; basal radii 

7 to 8. Brachydeuterus leuciscus (Gunther). San Juan Lagoon, 

Rio Ahoma, Mexico (Albatross). (Haemulidae) 
Lateral circuli (except the innermost) directed upward above. 22 

22. Submarginal elements of apical area appearing distinctly concave below (helmet-shaped); 

basal radii 8. 8 

Hcemulon steindachneri (Jordan & Gilbert). Gulf of California (Albatross). (Haemulidae) 























OBSERVATIONS ON FISH SCALES. 


H5 

Submarginal elements of apical area not appearing concave below. 23 

23. Submarginal elements of apical area hat-shaped. 

Cottogaster shumardi (Girard). Wabash River, Ind. (B. W. Evermann). (Percidae) 
Submarginal elements of apical area quadrate. 

Meniicirrhus saxatilis (Bloch & Schneider). Woods Hole, Mass. (Sciaenidae) 

Suborder SynentognaTh. 

BELONIDAJ. Marine gars. 

The houndfish, Tylosurus acus (Lacep&de) has irregular elongate (broad) scales with conspicuous 
concentric circuli, but no radii whatever. They thus recall the scales of Salmonidae. 

EXOC(ETIDAJ. Flying-fishes. 

Cypsilurus heterurus (Rafinesque) has large broad thin scales, about 10 mm. broad and 8 long; 
nucleus a short distance below middle; circuli strong, concentric, in some scales much more widely 
spaced laterally, and then often angled; margin wholly cycloid; about 4 or 5 strong basal radii (more in 
latinucleate scales), none apical. Except for the presence of radii, this is very similar to Tylosurus. 
It seems also to lead toward the scombrid type. 

HEMIRHAMPHIDAE. Halfbeaks. 

Hyporhamphus unifasciatus (Ranzani), from Woods Hole, Mass., has very broad scales, about 5 mm. 
long and 8, or slightly over, broad; apical margin broadly rounded; laterobasal comers rounded but 
evident; middle of base with a broad median lobe, which may be bilobed; basal radii two or three, 
widely diverging; nucleus near middle, but indistinct; apical field entirely covered with very fine 
transverse circuli, except a slender sculptureless submarginal band; basal field with transverse more 
widely spaced circuli, bending upwards and still more widely spaced in the lateral fields, and ulti¬ 
mately, when not reaching the margin, forming acute angles with the adjacent circuli of the apical 
field. The transverse dense apical circuli remind one of Xystcema (Gerridse), but in Xystcema there 
is no sign of lateral angulation, and the apical marginal region is entirely different. 

The scale of Hyporhamphus is evidently a further development, much more extreme, of the type 
of Cypsilurus. It also seems to point clearly in the direction of the scombrids. 

SCOMBRESOCIDAE. Sauries. 

The billfish, Scomhresox saurus (Walbaum) represents a still more extreme development along the 
lines of Hyporhamphus. The thin scale is about 5 mm. long and 8 broad, without angles or radii. The 
circuli are everywhere completely transverse, denser on the apical than the basal half, the two halves 
separated in some cases by more or less of an interval about the middle. At each extreme side is a 
thin zone, sculptureless except for a few irregular lines. The scales are of the same general type as 
those of the Scombridae and Cheilodipteridae. 

So far as seen, the synentognathous families may be separated thus: 


Apical and basal circuli about the same. 1 

Apical circuli transverse, denser than basal. 2 

1. Radii absent.Belonidae 

Basal radii strong.Exoccetidae 

2. Without radii.Scombresocidae 

With radii.Hemirhamphidae 


If doubt should arise owing to the apical circuli of Scombresocidae not being much denser than the 
basal, the family will still be easily recognized by the completely transverse character of the circuli, 
so that the effect of lateral angulation is lost. Dr. Jordan states that Regan (1911) recognizes an order 
Synentognathi, with one suborder for the belonids and scombresocids, and another for the hemirham- 
phids and exoccetids. The scale characters would not have suggested this arrangement. 

89970°—13-3 










146 


bulletin of the bureau of fisheries. 


Suborder Percesoces. 


ATHERINIDiE. Silversides. (PI. xxxvi, fig. 25.) 

For a general account of the scales of this family, see Proceedings of the Biological Society of Wash¬ 
ington, volume xxiii, pages 47-48. The genera Kirtlandia and Menidia are discussed, and the resem¬ 
blance to the scombrids is noted. All the scales except Kirtlandia have distinct basal radii, with the 
lower margin usually scalloped; the laterobasal angles are distinct, and there are distinct apical radii 
in some forms, as Chirostoma. The following key separates the species before me: 

Lateral and apical circuli alike and continuous, the circuli very widely spaced; scale very small, 
less than i}4 mm. broad, strictly cycloid; no apical radii; basal radii well developed, about 5 
or 6; laterobasal angles rectangular. 

Atherinops regis Jenkins & Evermann. (Algodones Lagoon, Mexico; Albatross) 

Lateral circuli strongly differentiated from apical, or the latter modified or partly suppressed... 1 

1. Apical margin scalloped or lobulate. 2 

Apical margin entire. 3 

2. Scale much broader than long; basal margin undulate, with a single large lobe; apical margin 

irregularly lobed, with traces of radii; basal radii reduced to one or two broad folds, no true 
radii; apical field without sculpture, but across the middle of the scale, apicad of the regular 
circuli, is an area of very fine longitudinal lines, in the middle on the apical side breaking into 

very fine labyrinthiform markings. Kirtlandia laciniata (Swain). (Chesapeake Bay, Va.) 

Scale little (sometimes not at all) broader than long; basal margin more or less angulate in the 
middle; apical margin finely irregularly scalloped, with evident though slender radii; basal 
radii about 7 to 10, well developed; lateral circuli very widely spaced, but apical field 
with extremely fine transverse circuli, which are much broken, and in the nuclear area mostly 
reducedto dots.. Chirostoma crystallinum Jordan & Snyder. (Lake Chapala, Mexico; J.N. Rose) 

3. Basal radii distinct; lateral circuli very widely spaced; apical circuli transverse, very dense, 

more or less broken, toward the nucleus reduced to granules; apical radii very slender, 
irregular, not always evident. 

Menidia peninsulce (Goode & Bean); M. menidia (Linnaeus); M. notata (Mitchill) 

Of this series, Chirostoma is possibly the most primitive, but Atherinops stands apart and has the 
primitive character of continuous, uniform circuli in the lateral and apical regions. Kirtlandia seems 
much modified, but hardly from a Menidia- like basis. Probably Atherinops and its allies should form 
a distinct subfamily. 

The scales of Menidia notata described in my paper cited above were not adult; other scales from 
the Bureau of Fisheries collection are about 3.5 mm. broad, with the apical margin subangulate or 
roof-like in profile. 

MUGILIDAk Mullets. 


The white mullet, Mugil curcema Cuvier & Valenciennes, from the collection at Woods Hole, has 
large rounded scales, with a straight, medially emarginate base; length about 9.5-10 mm; breadth 
11-11.5; basal radii few, crowded about the middle of the scale; nucleus apicad of middle; lateral 
circuli coarser than basal; apical margin minutely ctenoid, the apical region with the minutely imbri¬ 
cated structure of typical ctenoid scales. 

Here, then, we first meet with the typically ctenoid type of scale, as developed among the Acan- 
thopterygians. The ctenoid scales of certain Characinidae are of an entirely different character. 

There is no evident connection between the scales of Mugil and those of the Atherinidae. 

SPHYR7ENID7E. Barracudas. . 


The scales of Sphyrcena are very peculiar, and wholly unlike those of the Atherinidae or Mullidae. 
5. picuda Bloch & Schneider, from Tampa, Florida, has relatively large reddish scales, about 7 mm. 
long and a little over 6 broad, the lateral and basal margins gently convex, laterobasal comers obtuse, 
the apical region thin and without sculpture. The sculptured part of the scale has throughout extremely 
dense circuli, which, except in the upper lateral region, are interrupted by very numerous radii. The 
radii are very uniform, about 5 to 9 to a millimeter of the margin. The midmost circuli are not only 
divided into short sections by the radii, but the sections themselves are cut at intervals by very fine 





OBSERVATIONS ON FISH SCALES. 


H7 


lines, so as to seem segmented. In S', borealis DeKay, from Woods Hole, the colorless scales have a 
diameter of hardly mm., and the fine radii, instead of continuously interrupting the circuli, are 
represented by series of minute round holes, which, however, coalesce in some places, producing a 
condition like that of the great barracuda, S', picuda. In the northern barracuda, S. borealis, the apical 
sculptureless area is very small or wanting. The sphyraenid scale is very suggestive of that of Gadus 
and allied genera. 


A'*'A A 
•A,-.; a: a 
A >'.yv A 
A >A 
A A 


Fig. 9. —Mugil (Mugilidae). Cte¬ 
noid area. Bureau of Fisheries. 



Fig. 10. —Sphyrcena borealis (Sphyraenidae). Sculpture. 
Bureau of Fisheries. The transverse strands are circuli. 


Jordan & Evermann state that the families Atherinidae, Mugilidae, and Sphyraenidae are closely 
related (Bulletin 47, U. S. National Museum, pt. 1, p. 788). They were associated together in the 
order Percesoces by Cope. Boulenger includes in Percesoces several other families, as Anabantidae, 
Stromateidae, Polynemidae, Scombresocidae, etc., stating that the group is perhaps only an artificial 
one, but “a gradual passage may be traced connecting the most aberrant types.” 

The scales would certainly suggest that the three families described above are not very closely 
related. 

Suborder Rhegnopteri. 


POLYNEMIDAE. Threadfins. 

Jordan states that the Polynemidae are allied to the Mugilidae, but differ from them and from all 
other fishes in the structure of the pectoral fin and its basal bones. In Boulenger’s arrangement they 
go in the Percesoces, following the Mugilidae. In Polydactylus octonemus Girard the scale is quite 



Fig. ii .—Polydactylus (Polynemi¬ 
dae). Apical teeth. Bureau of 
Fisheries. 



typically Acanthopterygian, with ctenoid apical area, nucleus apicad of middle, and well-developed 
basal radii. The scale is nearly as in Mugil, having the same basal emargination, but differing in the 
spreading basal radii. The minute elements of the apical area are not as in Mugil, the submarginal 
ones being truncate instead of pointed. 

Although there are differences, the scales would suggest that the Polynemidae are actually nearer 
to the Mugilidae than the latter to the Atherinidae or especially the Sphyraenidae. 




148 


BULLETIN OF THE BUREAU OF FISHERIES. 


Suborder Salmoperc.E. Trout perch. 

PERC 0 PSIDA 5 . Sand rollers. 

The trout perch, Percopsis guttatus Agassiz, from East Okoboji Lake, Iowa (Evermann), has broad 
sub triangulate scales, with the apical margin forming two sides of the triangle, each side with about 
17 sharp teeth. Nucleus very close to apex; circuli widely spaced; a slight tendency to basal plication, 
but no distinct radii. In the form of the apical region, with the nucleus very far apicad and the single 
row of sharp teeth, this reminds one of Gobius and its allies. In the Gobiidae, however, the basal radii 
are very well formed and numerous. 

Suborder Berycoidea. Berycoid fishes. 

BERYCIDAJ. Alfonsinos. 

Jordan & Fowler say of this family: “Covered with ctenoid, or cycloid, foliate, or granular scales." 
I have from the United States National Museum scales of Beryx splendens Lowe (fish 21 inches long) 
from Japan. They are about 8 mm. long and 9.5-10.5 mm. broad, with the exposed part colorless and 
the covered pale yellowish red. The apical margin is thin and rather irregular, wholly without teeth; 
lateral margins concave; laterobasal comers very prominent; lower margin convex, irregularly sub- 
crenulate; nucleus a short distance apicad of middle; basal circuli dense; weak basal folds in place of 
radii; broad apical region with growth lines but no circuli, and with scattered small round perfora¬ 
tions. These perforations in the apical region sometimes have elevated margins, and in the region of 
the nucleus their place is taken by small sharp spines. Probably they arise as spines in every case, 
and the spines breaking off leave perforations. Jordan & Fowler state that the scales of Beryx splendens 
“are furnished with fine prickles, giving a somewhat rough touch." In Beryx lineatus, as figured by 
Sauvage, the prickles or spines of the apical region are large and dense. In either case, the arrange¬ 
ment parallels that found in species of Macrurus, and it is interesting in this connection to note that 
Regan some years ago suggested that the Gadoids might have come from the same stock which also 
gave rise to the Berycidae. In Caulolepis subulidens Garman, as figured by Garman (Memoirs Museum 
Comparative Zoology, xxiv, 1899), the scales are extremely modified, but still have some of the spines 
or teeth. 

TRACHICHYIDAJ. Deep-sea berycoids. 

Garman, in the work just cited, figures the scale of Trachichthys mento Garman. It is transversely 
oval, without the laterobasal comers of Beryx, but it has a number of true berycoid spines in the sub- 
apical region. Boulenger refers the genus to Berycidae. 

HOLOCENTRIDAJ. Squirrel-fishes. (PI. xxxvi, fig. 26.) 

The scales of the Holocentridae resemble in shape those of the Berycidae, being broad, with prominent 
laterobasal angles. In every case, so far as known to me, the apical margin is armed with strong, straight, 
comb-like teeth. In some (especially Myripristis murdjan) the subapical region has spiniferous pits, of 
the same character as the spine-bearing holes of Beryx. The basal margin is straight or nearly so, except 
that in the middle it is thrown into one or more folds or lobes, indicative of the rudiments of a basal 
radial system. The scales are all broader than long, but those of Flammeo are not so conspicuously so as 
those of Holocentrus, and especially Myripristis murdjan; the last are larger than any of the others, about 
S^2 mm. long and 14K broad, strongly reddish. The basal circuli in all are excessively fine, more so 
than in Beryx splendens. The species examined are as follows: 

Myripristis murdjan (Forskal). Strongs I., Carolines (M. C. Z.). 

Flammeo scythrops. Hawaii. 

Flammeo sammara (Forskal). Hawaii. 

Holocentrus diadema Laceplde. Hawaii. 

Holocentrus laticeps Cuvier & Valenciennes. Kaui, Hawaii (M. C. Z.). 


OBSERVATIONS ON FISH SCALES. 


149 


Holocentrus xantherythrus Jordan & Evermann. Hawaii. 

Holocentrus microstoma Gunther. Samoa. 

The species of Holocentrus are so uniform in their characters that I can not construct a satisfactory 
key. There are, however, minor differences; e. g., the apical teeth of H. xantherythrus are much coarser 
than those of H. laticeps, and the basal radial folds are more prominent in H. diadema and laticeps than 
in the others. 

Finding that H. laticeps was not recorded from the Hawaiian Islands, I asked Dr. Garman to look 
at the specimens (M. C. Z., 3440). This he kindly did, and reports that the identification is correct. 

Sauvage, in his work on the fishes of Madagascar, has figured scales of Myripristis seychellensis , 
M. pralinus, M. horbonicus, Holocentrus (or Holocentrum) spiniferus, H. diadema, H. leo and Holotrachys 
lima. These show various peculiarities, but ail confirm the essential uniformity of the holocentrid type, 
and indicate its general affinity with that of the Berycidae. 

There is an evident resemblance between the holocentrid scale and that of Aphredoderus. 

POLYMIXIID^E. Barbudos. 

From the United States National Museum I have scales of Polymixia japonica Steindachner, from 
Japan (fish 7 J 4 inches long). They are very broad, with the same general shape and apical spines as 
Holocentrus , but the basal circuli are very much less dense, and the basal radial folds are very well 
marked, throwing the basal margin into numerous strong undulations. The laterobasal corners are less 
prominent than in the holocentrids, and the subapical region is without spines. Thus the Berycoidea, 
as regards their scales, form a sufficiently compact group, quite isolated from the groups standing on 
either side of it in the system. 

Suborder Percomorphi. Perciform fishes. 

Superfamily SCOMBROIDEA. Mackerel-like fishes. 

Broadly speaking, the families Scombridae, Carangidae, Cheilodipteridae, Stromateidae, Hemirham- 
phidae, Scombresocidae, Belonidae, and Exocoetidae maybe ranged together (and apart from the percoid 
series) on their scales. Atherinidae show some resemblances also. The fishes are of course variously 
diverse in other characters. 

SCOMBRIDAE. Mackerels. 

I have figured the scales of Scomber in Smithsonian Miscellaneous Collections, volume 56, no. 1. 
They are small and thin, broader than long, with the circuli transverse. In the common mackerel, 
Scomber scombrus (Linnaeus), from Woods Hole, the apical margin is more or less, but very irregularly, 
dentate, without the formation of definite structures like those on genuinely ctenoid scales. At these 
teeth the circuli are bent upward and angled, and this irregular waviness and angulation is seen here and 
there in the subapical field, indicating no doubt the teeth of an earlier stage. The fusiform area repre¬ 
senting the nucleus is below the middle of the scale, and on each side of it the circuli are acutely angled. 
The circuli above the nucleus are somewhat denser than those below. The angulation of the lateral 
circuli in 5. scombrus is like that of the basal ones in Macrurus. 

In the bonito, Sarda sarda (Bloch), and the frigate mackerel, Auxis thazard (Lacep&de), the scales 
are of the same general type, but still smaller and more degenerate, often practically without sculpture. 
Those of Auxis are often pointed laterally. 

CARANGIDaE. Cavallas, etc. (PI. xxxvi, fig. 27.) 

The jack, Caranx hippos (Linnaeus), has circular scales about 2mm. diameter, with central nucleus 
and fine concentric circuli, not unlike some salmonid. There are no radii or marginal teeth. The inner 
circuli are variously angled laterally, and in the young the scales are transversely oval, and look just 
like those of Scomber. The carangid and scombrid scales are therefore very closely allied, although when 
adult appearing different. 


150 


bulletin op the bureau of fisheries. 


CHEILODIPTERIDAS. Bluefishes. 

The bluefish, Cheilodipterus saltatrix (Linnaeus), from Onset, Mass., has scales slightly over 2 mm. 
long and about 3 broad; apex broadly rounded, base flattened, slightly and obtusely angled in the 
middle; laterobasal comers rounded but evident; no radii; circuli transverse apically and basally, more 
or less angulate laterally; nucleus below the middle. The lateral circuli are often angulate only on one 
side. The apical margin is thin, and when not worn off is irregularly dentate; the coarse circuli are not 
deflected or angled below these teeth, as they are in Scomber. This scale is entirely of the scombrid 
type. 

STROMATEIDAE. Butterfishes. 

Gobiomorus gronovii (Gmelin), the Portuguese man-of-war fish, has feeble cycloid scales with 
widely spaced circuli which are more or less wavy. There are no radii. My material is perhaps imma¬ 
ture. In the butterfish, Poronotus triacanthus (Peck), from Woods Hole, the scales are as in Cheilodip¬ 
terus except that there are no signs of apical teeth, while the base often has one or two broad radial folds. 
The lateral circuli are angulate in most scales. 

The pilot-fish, Palinurichthys perciformis (Mitchill), has quadrate scales about ypi nun. long and 
broad; laterobasal corners distinct; nucleus below the middle; circuli very distinct, the basal denser 
than the apical, the lateral vertical, parallel with the margin; four or five indistinct basal circuli. This 
scale is like that of the lake herrings, Leucichthys, and does not at all suggest that of the Scombridae and 
allies. Jordan & Evermann separated the Centrolophidae (Centrolophus and Palinurichthys) from 
Stromateidae, but Jordan has more recently made Stromateidae include both Centrolophidae and Nomeidae 
(Gobiomorus). The scales would strongly suggest that Centrolophidae, at least, are a valid family. 
There is a striking general resemblance between the scale of Palinurichthys and that of Chirostoma crystal- 
linum Jordan & Snyder (Atherinidae), but the apical region of the Chirostoma scale is quite different. 

PEMPHERIDA 3 . Deep-water Catalufas. 

Pempheris otaitensis (species perhaps wrongly determined) from the Red Sea (M. C. Z.), has scales 
which differ greatly in size on the same fish. The larger ones are about 4 mm. long and 6 broad; strictly 
cycloid, with circuli all around, transverse in the apical region; no apical radii; nucleus basad of 
middle; laterobasal comers rounded; about 15 strong basal radii, arranged fan-like, the basal margin 
strongly crenate. This scale, while very different from that of Palinurichthys, shows enough resemblance 
to suggest affinity. 

Superfamily PERCOIDEA. 

CENTRARCHIDAJ. Sunfishes and basses. 

Mr. B. A. Bean very kindly sent me from the United States National Museum a very full set of 
centrarchid scales, with numbers only, so that I might classify them without any bias derived from a 
knowledge of their generic and specific identity. This I did, and afterwards the names and localities 
were supplied. The result was that I found the group to be on the whole a very compact one, the 
principal differences being found in the development of the apical teeth (the ctenoid feature), the 
density of the apical circuli, and the number of basal radii. The scales are quadrate or subquadrate in 
form, sometimes (Micropterus dolomieu) longer than broad, others (as Lepomis gibbosus) broader than 
long. No doubt the forms with well developed apical teeth are the most primitive (at least as regards 
their scales), the centrarchid type being originally ctenoid. It is interesting to note that Archoplites 
interruptus from San Francisco, the only fresh-water percoid west of the Rocky Mountains, has very 
strongly ctenoid scales, and the basal radii with an extremely minute beading. It is remarkable that in 
other forms the ctenoid margin is lost as the scale matures, thus: 

(1) Ambloplites rupestris, rock bass; young from Sodus Bay, N. Y., show a ctenoid V-shaped apical 
area, the apical margin with many sharp teeth; adults from Manchester, Va., show a perfectly 
entire apical margin, though (except in latinucleate scales) the V-shaped ctenoid patch is still 
visible as a sort of latticework pattern, failing below the margin. This is very different from 
the broad ctenoid area of Archoplites, the lower margin of which, in well-developed scales, 
is nearly straight. 


OBSERVATIONS ON FISH SCALES. 


151 

(2) Micropterus salmoides, large-mouth black bass; young from Sodus Bay, N. Y., show in most 
(but not all) scales a V-shaped ctenoid area, with teeth projecting slightly beyond the margin; 
scales of about the same age, from Falmouth, Mass., show the same, but are considerably nar¬ 
rower; adults from Bemus Point, N. Y., show a very broad ctenoid area, but the margin is tooth¬ 
less, or with extremely short and feeble projections. M. dolomieu is without ctenoid features 
at any age, though the apical circuli sometimes become sharply zigzag. 

Scales of Enneacanthus gloriosus, from Washington, D. C., are strongly ctenoid, the ctenoid area very 
broad and the marginal teeth distinct; they differ conspicuously from those of Archoplites by their 
broader form, more minute apical teeth, and more numerous (usually 12 or 13) basal radii. 

Chcenobryttus gulosus, warmouth, from Washington, D. C., has variably ctenoid scales, the ctenoid 
area sometimes reduced to a very small patch. A hybrid between C. gulosus and Lepomis gibbosus, 
from the District of Columbia, has the ctenoid feature well developed, the area broad. 

I could find nothing in the scales to justify the division of Lepomis into Apomotis, Lepomis, and 
Eupomotis. In the classification made without knowledge of the names, nearly all the species with 
intermediate characters—poorly developed but visible ctenoid features—fall in Lepomis, which is thus 
fairly compact on scale characters; but the so-called genera segregated from Lepomis are inextricably 
mixed. In the blue-gills Lepomis pallidus and holbrookii the apical margin is entire in some specimens, 
herein agreeing with the normal condition of Pomoxis. A disturbing feature is the great variability of 
some of the species, not only individual but racial. I give some examples: 

(1) Micropterus salmoides (Laceped&), large-mouth black bass. Scales from Falmouth, Mass., nar¬ 
rower than those from Sodus Bay, N. Y. 

(2) Lepomis gibbosus (Linnaeus), pumpkin-seed, from Washington, D. C., with the ctenoid area large, 
though the teeth are rudimentary; from Upper St. Croix River, Douglas County, Wisconsin 
(Graenicher), with widely spaced transverse apical circuli, and the ctenoid patch either wholly 
absent or reduced to a few marginal teeth of small size. 

(3) Lepomis holbrookii (Cuvier & Valenciennes), from the Carolinas, has the scale very broad (about 
6| mm. long and 8| broad), with the ctenoid features distinct; other scales, also from the Caro¬ 
linas, are much narrower and less ctenoid. 

(4) Lepomis cyanellus (Rafinesque), green sunfish, from Washington, D. C., and New Orleans, La., 
is conspicuously ctenoid when not latinucleate; from Woods Lake, near Greeley, Colorado 
(Warren), it is completely cycloid, with widely-spaced apical circuli. 

It will be observed that these variations follow rather narrow lines, and the racial differences are of 
the same sort as the individual ones. It remains to be seen whether the apparent racial differences in 
scale characters, as in color and other features, are the direct result of environmental conditions, or in¬ 
dicate incipient species. It would seem likely enough that there are, in fact, a number of unrecognized 
subspecific types among the centrarchids, and the individual variability noted may be due in large part 
to the crossing of such types, which have remained distinct only as long as isolated. 

The following systematic treatment mainly follows the lines of Jordan & Evermann’s work: 

Subfamily CENTRARCHIN#. 

Scales strongly ctenoid, the ctenoid patch very broad, though the teeth are very small; basal radii 

about 8 to 12; apical circuli quite dense. Centrarchus macropterus (Lacep&de) Dismal Swamp 

Scales cycloid or with a small ctenoid patch; apical circuli dense, not differing from the lateral ones... 1 

1. Scales yellowish, about as long as broad; basal radii 6 to 12. Pomoxis 

annularis Rafinesque, Neosho River, Mo., and P. sparoides (Lacep&de) New Orleans, La. 
Scales white, broader than long; basal radii 12 to 14. P. sparoides 

Sodus Bay, N. Y., and St. Croix River, Douglas Co., Wis., the latter from Dr. Graenicher. 

Are there northern and southern races of P. sparoides ? 





152 


bulletin of the bureau of fisheries. 

Subfamily LEPOMINAL 
Tribe Ambloputini. (Pl. xxxvn, fig. 29, 30.) 


Strictly cycloid, but the apical circuli widely spaced, and more or less strongly undulate or zigzag, as 

in Gerridae. Acantharchus pomotis (Baird), Tarboro, N. C. 

Sharply ctenoid when young, but margin cycloid in adults. Ambloplites rupestris (Rafinesque) 

With a small variously developed ctenoid area.*. Cheenobryttus gulosus (Cuvier & Valenciennes) 

Very strongly and coarsely ctenoid. Archoplites interruptus (Girard) 


Thus Centrarchus stands at the base of the Centrarchinae, and Archop lites at the base of the Amblo- 
plitini. 


Tribe Lepomini. (PI. xxxvn, fig. 28.) 


For the pharyngeal characters, see Bean & Weed, Proceedings United States National Museum, 
volume 40, pages 369-376. On the scale characters, Enneacanthus stands at the base of this series. 

Scales strongly ctenoid. Enneacanthus gloriosus (Holbrook) 

Scales moderately ctenoid, not so broad as those of Enneacanthus. 

Mesogonistius chcetodon (Baird) Trenton, N. J. 
Scales feebly ctenoid, rarely practically cycloid, with no generic difference from the last, except that 
they are usually less ctenoid and have fewer basal radii. Lepomis 

It seems impossible to make any key for the scales of the species of Lepomis; L. gibbosus, cyanellus, 
punctatus, auritus and some euryorus have the apical circuli more widely spaced than in the others. 
The species examined are L. cyanellus, punctatus, symmetricus, auritus, megalotis, pallidus, albus, heros, 
holbrooki, euryorus, gibbosus. The scale of L. megalotis (Lake Maxinkuckee, Ind.) is quite broad, 
with up to 12 basal radii, a larger number than is usual in the genus. 


Subfamily MICROPTERINAL Black basses. 

The genus Micropterus has been discussed above. The scales are the largest found in the Cen- 
trarchidae, but Ambloplites runs them close. Ambloplites differs from Micro pterus in having the adult 
scales conspicuously broader than long, with denser apical circuli. It is a question whether M. salmoides 
should not be called Aplites salmoides, or Aplites Rafinesque at least used in a subgeneric sense. 

The following arrangement of the centrarchid genera is suggested: Centrarchus, Pomoxis; Aplites, 
Micropterus; Archoplites, Chcenobryttus, Ambloplites, Acantharchus; Enneacanthus, Mesogonistius 
Lepomis. 

APHREDODERIDAL Pirate perches. 


Subfamily Aphredoderinaj. 

Aphredoderus sayanus Gilliams. Houston, Tex. (Evermann). Scales about 2^ mm. long and 
1% broad, parallel-sided, with four very deep basal plications, the basal margin strongly scalloped; 
apical margin with a row of about 25 to 30 very long teeth, free only at apex; nucleus subapical; 
nuclear area with fine labyrinthiform markings; lateral circuli widely spaced, but with rudiments 
of others between them. This is very different from Per cop sis, though agreeing in having a single 
row of apical teeth. Except for the ctenoid feature, there is a rather strong resemblance to Lucius. In 
the character of the ctenoid fringe, there is much resemblance to the ctenoid Characinidse of Africa. 
The ctenoid structures in Percopsis and Aphredoderus are quite different from those in Perea, but a 
fairly intermediate type occurs in Pomacanthus arcuatus (Linnaeus). 

Subfamily Trichophanin^E. 

Trichophanes foliarum Cope, from the Miocene shales of Florissant, Colo., has been discussed and 
figured in the American Naturalist, volume xui, pages 570-574. It is there regarded as the type of a dis¬ 
tinct family, but I now believe that it deserves only subfamily rank. The scales have a subapical 







observations on eish scales. 


153 


nucleus, very coarse concentric circuli, and about 15 or more very long and strong sharp spines along the 
apical margin. Thus the scales agree in all essential features with those of Aphredoderus, and in their 
marginal teeth closely resemble Xenochares and Distichodus in the African characinid fauna. 

The Aphredoderidae seem quite out of place next to the Centrarchidae. Jordan says of them: 

“ Probably the most primitive of all living Percoid fishes, showing affinities with the Salmopercae.” 
Aphredoderus “agrees with the Berycoid fishes in scales and structure of the fins, and Boulenger places 
it with the Berycidae. ” However, the resemblance to the berycoid scales is remote. In the Aphre¬ 
doderidae the apical teeth are articulated, as it were, on the margin, and in both the living and fossil 
fishes are movable. In the berycids they are in¬ 
stead rigid projections on the marginal area, into 
which they are basally prolonged. 

Regan has recently referred the Aphredoderidae 
to the Salmopercae. 

KUHLIID^. 

Kuhlia rupestris (Cuvier & Valenciennes) from 
Mauritius (M. C. Z. 5710)has rather large subquad¬ 
rate scales, about 10 mm. long and broad, the latero- 
basal comers rectangular, and the lower margin 
nearly straight. The nucleus is about 6 mm. from 
the base; apical region typically ctenoid, of the usual Percoid type, the apical teeth numerous and 
sharp, the submarginal elements truncate (style of Lagodon in Sparidae); basal radii delicate, about 
eleven. This agrees very well in general type with Lucioperca. 

PERCIDiE. Perches. 

The typical percid scale is subquadrate, ctenoid, with nucleus apicad of the middle, and strong 
basal radii. The American subfamilies are separated on the scales as follows: 

Basal radii many or few (e. g., 20 in some Hypohomus, 6 in some Boleosoma ); basal margin not very 
deeply crenate; submarginal apical elements short and broad.Etheostominae 

Basal radii few; submarginal apical elements quadrate; scales larger.. 1 

1. Basal margin very deeply crenate..Percinae 

Basal margin not very deeply crenate.Luciopercinae 

In the Old World we find the following subfamilies: 

Basal margin very deeply crenate or lobed; dorsal fins distinct; no canine teeth {Perea). . .Percinae 

Basal margin moderately crenate or lobed.• - ...• 1 

1. Submarginal apical elements short and broad; marginal teeth long ( Zmgel ).Etheostominae 

Submarginal apical elements longer, more quadrate; marginal teeth usually shorter. ... 2 

2. Dorsal fins distinct (and other characters)... Luciopercinae 

Dorsal fins united (etc.).Acermmae (Acenna) 

I have not examined the genus Percarina. 

In spite of the great development of Percidae in North America, the group must surely have origi¬ 
nated in the Old World, because (1) it is more varied in type there, and (2) it is more difficult to separate 
the European subfamilies than the American on their scales. However, the palaeontological evidence 
indicates considerable antiquity for the percids both in Europe and America, and even if it is true that 
the living American subfamilies are of Old World origin, this does not prove anything regarding the 
history of the much older forms known as fossils. 

The Lucioperca-Acerina type of scale is doubtless the primitive one in the family. It is difficult to 
find much difference between the scales of these genera, so different in other respects; but in Acerina 
the sub marginal apical elements are more conspicuously broadened basally, approaching the condition 



Fig. 13.— Aphredoderus sayanus (Aphredoderidae). Marginal 
teeth. Bureau of Fisheries. 


/ 












154 


bulletin of the bureau of fisheries. 


of the Etheostominae very noticeably, whereas in Lucioperca they are more nearly as in Perea. This 
character varies, however, in Lucioperca, and in L. sandra Cuvier & Valenciennes, from the Danube, 
the submarginal elements are quite short. L. volgensis Pallas, from Astrachan, has the submarginal 
elements conspicuously elongated. Boulenger unites the American Stizosiedion with Lucioperca , and it 
is impossible to find any substantial difference in the scales. Curiously, the pike perch, Stizosiedion 
vitreum (Mitchell) from Cedar Point, Toledo, Ohio, has the submarginal elements elongated as in L. 
volgensis; while S. canadense (C. H. Smith) from Big Sycamore Creek, Tenn., has them short as in L. 
sandra. 

The species of Acerina examined are A. cernua Linnaeus (Danube River and Switzerland) and A. 
schroetser Linnaeus. I can not separate them on the scales. Acerina acerina (Perea acerina Gmelin) I 
have not seen. The genus Zingel Cloquet includes Z. zingel Linnaeus, Z. asper (Linnaeus) and Z. streber 
(Siebold), unless we follow Jordan, and recognize a second genus ( Aspro Cuvier & Valenciennes) for 
the second and third of these. I have Z. zingel and Z. streber. The scales of Z. streber, at least in my 
material, are smaller and shorter, otherwise there is no appreciable difference. Scales of Z. zingel (fish 
10% inches long) are about 4 mm. long and 3% broad, therefore much larger than any of the American 
Etheostominae, the largest of which are less than 2 mm. long. In the larger American scales ( Percini 
and Dip lesion) the basal radii are much stronger than in Zingel, and more parallel. Jordan remarks 
that Zingel is perhaps the ancestor of the entire group of Etheostominae. 

Of Perea I have the three known species, European perch, P. fluviatilis Linnaeus, from Sweden; 
American perch P. jlavescens (Mitchell), from Lyndonville, Vt., and Falmouth, Mass.; P. schrenkii Kessl 

from Khuldscha. P. fluviatilis (fish 17 inches long) 
has large reddish scales, fully 10 mm. long, with six 
basal radii; basal margin deeply cut into long lobes; 
apical teeth short; subapical elements quadrate, but 
not elongated. P. jlavescens (fish 6 inches long) has 
colorless scales about 4 mm. long; six basal radii; 
lobes of basal margin not so long; apical teeth short; 
subapical elements distinctly elongated. In P. schrenkii the scale is about the same size as that of P. 
jlavescens, but longer, and broader above the middle than at the base, the reverse being conspicuously 
true of P. jlavescens. The basal radii are three to six, and the lobes of the basal margin are shorter than 
in either of the other species. The apical marginal elements are distinctly elongated. Scales of P. 
schrenkii are readily known from those of Lucioperca volgensis by their peculiar form, narrowing below 
(basad), the shorter apical teeth, and the much more strongly crenate base. 

It seems quite impossible to make a key to the genera or species of American darters, Etheostominae. 
I give a list of the species studied, with some notes. 

Percina caprodes (Rafinesque), log perch. Chili, Ind. Scales about 1% (some 1%) mm. long, 
and about as broad; about 6 to 10 basal radii; apical teeth long. 

Hadropterus phoxocephalus (Nelson). Durkey’s Ferry, Wabash River, Ind. 

H. macrocephalus (Cope). Obeys River, Olympus, Tenn. 

H. aspro (Cope & Jordan), black-sided darter. Upper Eel River, Allen Co., Ind. 

H. guntheri (Eigenmann & Eigenmann). Cheyenne River, Valley City, N. Dak. 

H. peltatus (Stauffer). Neuse River, Raleigh, N. C. 

H. ouachitce (Jordan & Gilbert). Marked Tree, Ark. 

H. scierus Swain. Tippecanoe River, Marshland, Ind. 

H. roanoka (Jordan & Jenkins). Neuse River, Raleigh, N. C. “Cotype.” 

H. maxinkuckiensis Evermann. Lake Maxinkuckee, Ind. 

All have small scales with quite long apical teeth. They differ in size; thus H. macrocephalus has 
scales hardly over 1 mm. long, while H. peltatus has them fully 1.5 mm., the fishes in each case being 3 
inches long. H. peltatus and scierus have scales of about the same size, but the apical teeth are distinctly 
longer in scierus. 


JL-Ji-JL-J. 



Fig. 14. — Percaflavescens( Percidae). Ctenoid structures. 
Bureau of Fisheries. 




OBSERVATIONS ON FISH SCALES. 


155 

Hypohomus spilotus (Gilbert). Hector Creek, Ky. (Woolman). Scales known from those of Hadrop- 
terus by the very large number of basal radii. 

Cottogaster uranidea (Jordan & Gilbert). Vincennes, Ind. 

C. copelandi (Jordan). Iowandi, Ky. 

C. shumardi (Girard). Durkey’s Ferry, Wabash River, Ind.; also Wabash River, Ind. (Evermann). 

C. cheneyi Evermann & Kendall. Rackett River, N. Y. “Cotype.” This genus has small 
scales like those of Hadropterus, with the basal radii only moderately numerous (e. g., 9 or 10), 
but the scales are conspicuously broader than long, averaging considerably shorter than those 
of Hadropterus. 

Ulocentra stigmcea (Jordan). Obeys River, Olympus, Tenn. 

U. gilberti Evermann & Thobum. Walker’s Ford, Clinch River, Tenn. “Cotype.” 

U. meadice Jordan & Evermann. Indian Creek, Tenn. “Cotype.” 

U. histrio (Jordan & Gilbert). Black Rock, Rock River, Ark. 

U. simotera (Cope). Mount Verde, Tenn. 

U. “probably new.” Arnwine Creek, Athens, Tenn. 2inches long. 

Ulocentra has broad scales like those of Cottogaster, but the basal radii are more numerous (generally 
about 12), and the apical teeth are shorter, usually very short. U. stigmcea has very broad 
scales, some almost twice as broad as long, whereas in U. gil¬ 
berti they are mostly not greatly broader than long. 

Diplesion blennioides (Rafinesque), green-sided darter. Murfrees¬ 
boro, Tenn., 5 inches long. Scales xpi mm. long and broad, 
with long apical teeth and about a dozen basal radii. The 
scales are larger than those of Ulocentra, Cottogaster, etc., but so 
is the fish. I can not satisfactorily distinguish Diplesion scales 
from those of Percina. 

Boleosoma longimanus (Jordan). Lexington, Va. 

B. podostemone (Jordan & Jenkins). Roanoke River,Va. “ Cotype.” 

B. nigrum (Rafinesque). Osterville, Mass., and Columbia City, Ind. 

In this genus the scales are broader than long, with about a dozen basal radii. 

Crystallaria asprella (Jordan). Wabash River, Ind. 3 inches long; extremely small, rather broad 
scales, with long apical teeth. 

Ammocrypta pellucida (Baird), sand darter. Adamsboro, Ind. 3 inches long. 

A. beanii Jordan. Greenville, Ala. inches long. The scales of this genus are also extremely 
minute, almost rudimentary. 

loa vitrea (Cope). Raleigh, N. C. Scales minute, with long apical teeth; the principal character 
is found in the very widely spaced lateral circuli. The last three genera are the weakest scaled 
in the family. 

Etheostoma. In this large genus the scales are of the same type as those of related genera, with 
pigment spots along the bases of the apical teeth, such as are found in other American Etheo- 
stominae, in Zingel, and even in Acerina cernua. The basal radii vary from 9 (zonale, flabellare) 
to 16 (some pottsii, julice, and iowce). In some species the scales average about as broad as long 
(punctulatum), in others they are conspicuously broader than long ( julice, pottsii), but in no case 
are they longer than broad, if we take scales from the middle of the side and measure only to the 
bases of the apical teeth. In some the scales are comparatively large ( variatum ), in others 
very small ( flabellare ). After measuring what seemed to be fair average scales of each species, 
I have thrown my results into the following key, but it must be clearly understood that while 
it is indicative of general tendencies or types, it is not at all reliable for the determination of the 
species. 



Fig. 15. —Cottogaster shumardi (Per- 
cidae). Ctenoid structures. Bu¬ 
reau of Fisheries. 



bulletin of the bureau of fisheries. 


156 

The following abbreviations are used: long., lat., length and breadth; ap., length of longer apical 
teeth; b. r., number of basal radii; measurements all in microns, except the length of the fish. 

A. Length of scale less than 800. 

a. Breadth of scale same as length. 

E.ftabellare Rafinesque, fan-tailed darter (1 inch). Cumberland Gap, Tenn.; long. 

and lat. 590; lateral radii very widely spaced; 9 b. r. 

E. punctulatum (Agassiz) (1 inch). Marshfield, Ind.; long, and lat. 655; ap. 95; 
10 b. r. 

b. Breadth of scale much greater than length. 

1. Scale very broad; pigment spots along margin light brown. 

E. lepidum (Baird & Girard) (1% inch). New Braunfels, Tex.; long. 770, lat. 
1150; 12-14 b. r. 
ii. Scale moderately broad. 

E. australe Jordan. inch). Chihuahua, Mexico; very widely spaced 

circuli around nucleus; long. 775, lat. 93$; ap. 05; 12 b. r. 

E. camurum (Cope) blue-breasted darter (2^ inches). Marshland, Ind.; long. 
705, lat 880; ap. 95; 10 b. r. 

E. tippecanoe Jordan & Evermann (2 inches). Marshland, Ind.; long. 750, 
lat. 865; 9-12 b. r. 

B. Length of scale 800 to 1,040. 

a. Scale about as broad as long. 

E. cragini Gilbert (1 inch). Garden City, Kansas; “cotype”; long. 815, lat. 830; 
ap. 95; 12 b. r. 

E.jessice (Jordan & Brayton). Long. 1040, lat. 1055; ap. 145; 11-14 b. r. 

E. whipplii (Girard). {1% inch). Kaimishi, I. T.; long, and lat. 800; 10-n b. r. 

b. scale evidently broader than long. 

i. Basal radii 9. 

E. zonale (Cope) (1^ inch). Cumberland Gap, Tenn.; long. 990, lat. 1090. 
ii. Basal radii more than 10. 

E. iowce Jordan & Meek. Creighton, Nebr.; long. 800, lat. 1040; ap. 80; 14-16 
b. r. 

E. obeyense Kirsch (i *4 inch). Cumberland River, Wayne County, Ky.; long. 
865, lat. 945; ap. 95; 11-13 b. r. 

E. pottsii (Girard), inch). Chihuahua, Mexico; long. 960, lat. 1250; 15-16 
b. r. 

E. julice Meek. Springfield, Mo.; long. 1040, lat. 1295; 13-16 b. r. 

E. boreale (Jordan) (1% inch). Michigamme, Mich.; long. 925, lat. 1010 
(another, long. 880, lat. 925); 12-14 b. r. 

C. length of scale over 1040. 

a. Length of scale 1490, breadth the same. 

E. variatum Kirtland (2 inches). Blue River, Wyandotte Cave, Ind.; 11 b. r. 

b. Length of scale not over 1330. 

E. swannanoa Jordan & Evermann (ij£ inch). Black Mountain, N. C.; long. 
1055, lat. 1280; 10-13 b. r. 

E. squamiceps Jordan (iK inch). Murfreesboro, Tenn.; circuli around nucleus 
not very widely spaced; long. 1310, lat. 1375; ap. 72; 14 b. r. 

E. jordani Gilbert (2 inches). Oxford, Ala.; “ cotype; ’ ’ circuli around nucleus 
very widely spaced; long. 1170, lat. 1360; ap. no; 9-12 b. r. 

E. cinereum Storer (3^ inches). Olympus, Tenn.; long. 1330, lat. 1345; ap. 
128; 12 b. r. 

E. coeruleum Storer, blue darter. inch). Neosho, Mo.; long. 1120, lat. 1440; 
ap. 145; n-15 b. r. 

E. rufilineatus (Cope) (2^ inches). Knoxville, Tenn.; long. 1150, lat. 1200; 
ap. 145; 13 b. r. 

It will be observed that there is very little correspondence between this arrangement and the sub¬ 
genera recognized by authors. It is certain that the scales are of very minor value in the taxonomy of 
this group, and no doubt individual variation oversteps most of the limits suggested by my data. At 
the same time there are good average differences between several of the species; thus, when we compare 
the species, E. pottsii and E. australe, both from Chihuahua, it is evident that pottsii has larger and 
broader scales, and the difference is greater than can be accounted for by the somewhat larger size of the 
fish. It is probable that if statistical studies are made of numerous scales, some help will be obtained 
for the separation of closely allied species. 

Psychromaster tuscumbia (Gilbert & Swain). Tuscumbia, Ala. Scales broader than long, not 
differing from those of Etheostoma. 



OBSERVATIONS ON FISH SCALES. 157 

Boleichthys fusiformis (Girard). St. Francisco River, Ark. Scales broader than long, like those 
of Etheostoma, with prominent rectangular laterobasal comers; basal radii about 12 to 14. 
Microperca punctulata Putnam. Lake Maxinkuckee, Ind. Scales very small, conspicuously 
broader than long (length about 765 /*, breadth 1040); about 11 to 14 basal radii. Easily known 
from Boleichthys scales by the smaller size and obtuse laterobasal comers. 

M.fonticola (Jordan & Gilbert). San Marcos, Tex. Scales like those of M. punctulata. 

For the North American percid scales described above I am indebted to the Bureau of Fisheries, 
and for the European species to the National Museum, in each case through Dr. H. M. Smith. 

In general, the scales of the Percidae are quite distinct from those of the Centrarchidae, though of 
the same essential character. The scales of the two families approach in such genera as Archoplites and 
Lucioperca (L. sandra ), but in the Archoplites the nucleus is not so far apicad as in the other. 

The Validity of Boleosoma olmstedi (Storer), as Indicated by its Scales. 

BY T. D. A. COCKERELL AND MARY ESTHER ELDER. 

We recently received from the Bureau of Fisheries some scales of Boleosoma olmstedi 
(Storer), a form which has been treated as a subspecies of B. nigrum , but which Dr. W. C. 
Kendall believes to be a valid species. It was suggested that perhaps the scales might 



Fig. 16 .—Boleosoma ni¬ 
grum. Apicalmargin. 



i.-'tfei 


Fig. 17 .—Boleosoma po. 
dostemone. Apical 
margin. 



Fig. 18 .—Boleosoma 
olmstedi. Apical 
margin. From speci¬ 
men 3-j 1 * inches long. 



Fig . 19 .—Boleosoma olm¬ 
stedi. Apical margin. 
From specimen iVa 
inches long. 


afford characters which would throw light on the question of the distinctness of B. 
olmstedi. We hardly expected positive results, on account of the undoubted affinity 
of the fishes, but a study of the material shows that, at least so far as our material goes, 
the scales of B. nigrum and olmstedi are readily separable. The observed difference 
can not well be a matter of age, as olmstedi scales were examined from fishes 1H inch 
and 3^ inches, respectively, while the B. nigrum scales came from a fish 2X inches long. 
We also took occasion to compare scales of B. podostemone (cotype fish, 1 H inches long), 
and found good characters to distinguish them from those of the others. The scales of 
the three may be diagnosed as follows: 


(x) Boleosoma nigrum (Rafinesque). Columbus City, Ind. Apical teeth rather long, the greater part 
free from the marginal membrane; subapical elements below the teeth transversely elongated, 

and usually in four rows. 

( 2 ) Boleosoma podostemone (Jordan & Jenkins). Roanoke River, Va. Apical teeth very Jong, the 
' ’ greater part free from the marginal membrane; subapical elements below the teeth in two or 

three distinct rows, subtriangular in form. .. 

(,) Boleosoma olmstedi (Storer). Falmouth, Mass. Apical teeth moderate, less than half free from the 
(3 marginal membrane; subapical elements below the teeth in two or three distinct rows, sub- 

triangular. 







I5« 


BULLETIN OF THE BUREAU OF FISHERIES. 


APOGONIDaE. Cardinal fishes. 

In Apogonichthys pomarce Steindachner from the Society Islands (M. C. Z. 9698), the reddish scales 
are much broader than long, length about 4%, breadth about 5X nun.»' general character percoid; 12 to 16 
basal radii; laterobasal corners obtuse; lateral circuli numerous, oblique, running to the margin; apical 
teeth moderate; submarginal elements longer than broad, emarginate basally. Differs at once from 
Lucioperca, Centropristes, etc., by the oblique lateral circuli. The beginning of this obliquity is seen in 
Percichthys. 

SERRANIDiE. Sea basses. (PI. xxxvn, fig. 32.) 

The North American genera examined can be divided into subfamilies as follows: 

Serraninae ( Paralabrax, Centropristes). Apical marginal spines truncate. 

Epinephelinae ( Epinephelus ). Apical marginal spines obtusely pointed, margined. Scales much 
longer than broad. 

Moroninae ( Morone, Roccus ). Apical marginal spines pointed or (adult Morone) minutely bifid at tip. 
Roccus is easily separated from Morone by the very numerous basal radii. 

Another subfamily (Percichthyinae) must be recognized for the freshwater genus Percichthys Girard, 
in which the adult scales are longer than broad, parallel-sided, with the broadly rounded apical margin 
entire, although there is a submarginal ctenoid patch, beset with spines. 

Still another subfamily (Plesiopinae) must contain Plesiops Cuvier, of which I have P. corallicola 
from the Ebon Islands (M. C. Z., 2473). The scale is 7 mm. long and 6% broad, the exposed part covered 
with dark purplish skin. Laterobasal angles obtuse; nucleus in the submarginal apical region, and 
from it radiate about 15 long basal radii; lateral circuli dense, slightly oblique; apical marginal teeth 
slender, more or less obtuse or truncate at end; subapical elements narrow and elongate. This is nearer 
to Centropristes than to any of the other scales cited above. A lateral line scale of P. corallicola is 
curiously different, with the nucleus much further down, and having strong apical as well as basal radii 
Boulenger makes P. corallicola a synonym of P. nigricans (Ruppell). 

Scales of Aulacocephalus schlegelii Gunther (A. temminckii Bleeker) are figured by Sauvage in his 
work on the fishes of Madagascar. They somewhat approach those of Epinephelus. 

Subfamily PERCICHTHYINAE. The truchas. 

My material of this group is from the United States National Museum. 

Per cosoma melanops (Girard). Santiago, Chile; 4I inches long. Scales reddish, about 3 mm. long 
and 2 broad; parallel-sided, with the laterobasal corners more or less projecting downwards; nucleus 
about 2 mm. from base; 6 to 9 basal radii; lateral circuli coarse, somewhat oblique; ctenoid patch 
very variable in size, with long narrow elements, some of which occasionally project as spines 
over the margin. 

Percichthys trucha (Cuvier & Valenciennes). South America; 12X inches long. Scales reddish, the 
larger ones about mm. long and 4^ broad; nucleus about 3 mm. from base; basal margin slightly 
convex, delicately crenate; apical field as in Percosoma. In latinucleate scales there is no ctenoid 
patch, and the widely spaced apical circuli run right across, parallel with the broadly rounded 
margin. 

A young fish, 5X inches long, from Argentina, has scales less than 2 mm. long, but still without 
projecting apical spines. 

Although this fish is closely allied to Percosoma, the latter is readily separated by the long and 
narrow scales. 

Percichthys chilensis { Girard). Santiago, Chile; 7^ inches long. Boulenger makes this a synonym of 
P. trucha, and the scales seem the same, though the basal radii may average somewhat less. 


OBSERVATIONS ON FISH SCALES. 


159 


Subfamily SERRANIN.E. Sea basses. (PI. xxxvn,fig. 31.) 

The following have been examined: 

Centropristes striatus (Linnaeus), black sea bass. Woods Hole, Mass. Scales subquadrate, about 8 mm. 
long and broad; ctenoid area very beautifully developed; apical teeth truncate and often broadened 
at base; nucleus subapical; basal radii 9 or 10; lateral circuli running parallel with margin. 

Paralabrax maculofasciatus (Steindachner), spotted cabrilla. Guaymas, Mexico (Albatross). Scales 
about 4 mm. long and 2^ broad, the long, parallel-sided form very different from that of Centro¬ 
pristes; basal radii 8 to n. 



Fig. 20. —Epinephelus nivea- 
tus (Serranidae). Ctenoid 
structures. Bureau of 
Fisheries. 


JVjJV 

U* 

Young. 



Fig. 21.— Morone americana (Serranidae). Ctenoid structures. Bureau of 

Fisheries. 




Fig. 22.— Priacanthus (Priacanthidae). Fig. 23.— Pseudopriacanthus altus (Priacanthidae). 

Bureau of Fisheries. Bureau of Fisheries. 

Paralabrax clathratus (Girard), cabrilla. San Diego Bay (Albatross). Scales similar, but smaller, and 
somewhat broader in proportion to their length. In both species of Paralabrax the scales are white; 
the finely mottled skin has the pigment light ferruginous in P. maculatofasciatus, purplish-brown in 
P. clathratus . 

Subfamily EPHINEPHELINAL Groupers. 

Epinephelus niveatus (Cuvier & Valenciennes), snowy grouper, from Katama Bay, has scales which 
remind one of Paralabrax, but the basal radii are only 4 to 6, and the apical area is quite different, 
with the spines much reduced in number, but larger. 











i6o bulletin of the bureau of FISHERIES. 


Subfamily MORONINiE. White perches. 

The characters of Roccus and Morone are given in the table of Acanthopterygian scales on an earlier 
page. 


LOBOTIDAJ. Flashers. 


The flasher, Lobotes surinamensis (Bloch) has large subquadrate reddish scales, which resemble 
those of Roccus in the very numerous basal radii. Other characters are given in the table just cited. 

PRIACANTHim Catalufas. 

Two subfamilies may be distinguished as follows: 

Priacanthinae {Priacanthus) . Scales very strongly trilobed at base; apex produced, with irregularly 
placed teeth. 

Pseudopriacanthinae {Pseudopriacanthus). Scales quadrate (the apical margin produced to an obtuse 
angle), the base not at all trilobed, but its middle third crenate from the 5 or 6 basal radii; marginal 
teeth sharp and irregular, but not so irregular as in Priacanthus. 

All the specimens examined are from Woods Hole, Mass. The Pseudopriacanthus is P. alius (Gill). 
The Priacanthus is presumably P. arenatus Cuvier & Valenciennes, with which it agrees in fin rays, color 
of fins, etc., but it has a large serrate preopercular spine, as in P. crueniatus (Lacep£de). 

LUTIANIDAJ. Snappers. 

The scale of the gray snapper, Neomcenis griseus (Linnaeus), from Tampa, Fla., has been figured in 
Proceedings of the Biological Society of Washington, volume xxni, page 91. The mutton fish, N. analis 
(Cuvier & Valenciennes) is included in the table of Acanthopterygian scales above. The scale of N. 
griseus figured was much worn, and had lost the apical teeth, but the figure shows well the numerous 
basal radii, the lateral circuli running parallel with the margin, etc. 


HL-EMULIDiE. Grunts. (PI. xxxvn, fig. 33.) 

In the pigfishes, Orthopristis , the marginal teeth are truncate; in the grunts, Hcemulon , and the 
burritos, Brachydeuterus , they are pointed. From these and other characters perhaps two subfamilies 
(Orthopristinae and Haemulinae) maybe indicated. Jordan & Evermann say of the Haemulidae: “The 
group is very close to the Lutianidae on the one hand and to the Sparidae on the other, while some of 
its members show affinities with some Sciaenidae and Serra- 
nidae.” In its scales Orthopristis resembles some Sciaenidae, 
as the croakers Micropogon. 

The scale of Anisotremus virginicus (Linnaeus) is figured 
in Proceedings of the Biological Society of Washington, 
volume xxni, page 92. 

SPAR I DAS. Porgies. 

I have examined scup, Stenotomus chrysops (Linnaeus) 
from Woods Hole, Mass., and pinfish, Lagodon rhomboides 
(Linnaeus). Both have large scales, those of Lagodon quad¬ 
rate, about as broad as long, those of Stenotomus much 
broader than long. The broad apical field has the usual 
Acanthopterygian sculpture feebly indicated, but only the 
margin is distinctly sculptured, with the well-formed elements in two {Stenotomus) or three {Lagodon) 
rows. This condition leads in the direction of that found in the Gerridae. The basal radii are 12 in 
Lagodon, 13 or fewer in Stenotomus. The apical structure is nearly as in the coral fishes, Pomacentridae, 
while both resemble the surmullets, Mullidae. The scale of Lethrinus, as figured by Gunther, has very 
well-developed sculpture in the apical field, with 13 or 14 rows of minute teeth. 



Fig. 24. —Neomcenis analis (Lutianidae). 
Bureau of Fisheries. 




OBSERVATIONS ON FISH SCALES. 


161 


In Box vulgaris (Vienna Museum; M. C. Z.) the scales are about 334 mm. long and 5^ broad, with 
the nucleus central and about 10 widely spreading basal radial folds. This is much like Stenotomus, 
differing in the less apical nucleus; the sloping sides, making the lower margin the broadest part; the 
broad apical region with the small quadrate elements distinct over the greater part, with no marked 
difference between the marginal and submarginal ones; and the much more oblique lateral circuli. 
(PI. xxxviii, fig. 34.) 

Dr. G. A. Boulenger kindly collected for me scales of Dentex vulgaris Cuvier, from a fish 2 feet 10 
inches long, in the Grimsby Market. The scales vary very much in size and form; a large one is about 
21 mm. long and 27 broad; an unusually broad one is about 13 mm. long and 21 broad; another is 15^ 
long and 18 broad. These all come from the side of the fish. The circuli are excessively fine, and the 
lateral ones are little oblique, w r hereas in Box they are extremely oblique, reaching the margin at a large 
angle. The basal radial system is variably and often poorly developed, and the radii are not very numer¬ 
ous. The apical margin appears cycloid, but the apical field has a fine half obliterated honey-comb-like 


Fig. 25. —Orthopristis chalceus 
(Haemulidae). Ctenoid struc¬ 
tures. The spots between the 
teeth are ferruginous pigment 
spots. Bureau of Fisheries. 


Fig. 26. —Stenotomus chry- 
sops (Sparidae). Ctenoid 
structures. Bureau of 
Fisheries. 




structure representing the ctenoid patch. Curiously, the skin over the apical field is marked with a very 
distinct network of polygonal cells, corresponding to the structure beneath. The nucleus is apical of 
the middle. 

In Dr. A. S. Woodward’s Catalogue of Fossil Fishes (1901), and in earlier works, Dentex appears 
among the Percidse (sens. lat.). Dr. Woodward states that Dentex, Genes, etc., are intermediate between 
the Percidae and Sparidae. 

M£NIDj£. Picarels. (PI. xxxviii, fig. 35.) 


I have the scales of an undetermined species of Smaris (Spicara ) from Trieste (M. C. Z., 10436). 
They are about 2^ mm. long and 3% broad; nucleus a little above the middle; about 10 strong widely 
spreading basal radii; sides sloping, so that the base is much the widest part; lateral circuli extremely 
oblique, but wanting in upper lateral region; apical margin strongly angled in the middle; apical margi¬ 
nal teeth sharp, and below them about two rows of broad subquadrate elements, below which the apical 

field is almost without sculpture. . 

This may be regarded as an extreme development of the type of Box. The oblique lateral circuli 
also suggest Apogonichthys, which is, however, very different in the apical region. 

GERRIDj®. Mojarras. 


The “broad shad,” Xystcema cinereum (Walbaum), from La Paz Harbor (Albatross) has trans- 
versely oval or oblong scales about 6 mm. long and 7 broad, the laterobasal comers rounded, and the 
basal radii few (about 5) and more or less irregularly placed. The lower margin is only feebly cremate. 
The thin apical field shows rudiments of the usual ctenoid structures of Acanthopterygians, reduced to 

89970°—13-4 








bulletin of the bureau of fisheries. 


162 


irreguiar transverse lines and small marginal denticulations. The lateral circuli are transverse, entirely 
in the manner of a clupeid. This last character is remarkable; a certain approach to it is found in Steno- 
tomns (Sparidae), in which the upper lateral circuli are obliquely directed outward, pointing to the 
anterolateral angles. 

The scales of the silver jenny, Eucinostomus gula (Cuvier & Valenciennes), from Rio Grande do Sul, 
Brazil (M. C. Z., 16452) are so exactly like those of X. cinereum that I am at a loss to describe any differ¬ 
ence. Scales of E. gula from Tampa, Fla., received from Dr. Graenicher, differ by having the apical field 
almost entirely covered with transverse circuli (not so dense as those elsewhere), and the ctenoid patch 
hardly indicated by even a rudiment. It is possible that northern and southern races of E. gula 
exist? (PI. xxxvi it, fig. 36.) 

KYPHOSIDtE. Chopas. 

The “chopa blanca” or Bermuda chub, Kyphosus sectatrix (Linnaeus) from Menemsha Bight, Mass., 
shows a modified type of acanthopterygian scale, with a thickened band with hyaline dots across the 
middle, and the apical area having a grooved appearance. There are two rows of distinct elements on 



Fig. 27. —Lagodon rhomboides 
(Sparidae). Ctenoid struc¬ 
tures. Bureau of Fisheries. 



sectatrix (Kyphosi- 
dae). Apical teeth. 
Bureau of Fisheries. 



Fig. 29. —Xystcema cinereum (Gerridae). Apical sculp¬ 
ture. Bureau of Fisheries. 


the apical margin, the outermost ending in sharp teeth, and all triangular at base, approaching the 
condition found in Neomcenis (Lutianidae) and Chcetodon (Chaetodontidae). The scales are broad-quad¬ 
rate, rounded apically, with rectangular lower corners; length of scale about 5 mm., breadth about 
The basal radii are very few, 4 to 6. A constant peculiarity is the concavity of the sides of the apical 
margin. The lateral circuli are parallel with the margin. 

This family is evidently not allied to the Gerridae. 


MULLIDAJ. Surmullets or goatfishes. 

The characters of Mullus, Upeneus, and Mulloides have been given in the table of acanthopterygian 
scales above. In all these genera the lateral circuli are more or less oblique, and the basal radii are few. 

SCLENID^. Drums. 

Two subfamilies can be separated as follows: 

Otolithinae (Cynoscion), the weakfishes. Elements of apical marginal and submarginal area with 
median keel or ridge. 


a 



OBSERVATIONS ON FISH SCALES. 


163 

Sciaeninae ( Leiostomus , Micropogon, Menticirrhus), the drums. Elements of apical marginal and sub¬ 
marginal area without any definite median keel or ridge; apical teeth pointed (. Menticirrhus) or 
truncate. 

The specific characters are given in the table of acanthopterygian scales above. In all the lateral 
circuli run parallel with the margin. The squeteague Cynoscion regalis is quite different from the 



Fig. 30.— Upeneus (Mullidae). Ctenoid area. Bureau 
of Fisheries. 



Fig. 31. —Micropogon undulatus 
(Sciaenidae). Apical teeth. 
Bureau of Fisheries. 


others by the very numerous and densely placed basal radii, which, however, occupy only about the 
middle third of the scale. In all the apical elements run conspicuously in straight lines, producing a 
sort of fluted effect. 

LATILIDiF. Blanquellos. 

In the tilefish Lopholatilus chamceleonticeps Goode & Bean, from the Gulf Stream, the scales are 
subquadrate, the larger ones about 9 mm. long and 8 broad, the laterobasal corners rectangular. Nucleus 
subapical; about five basal radii coming from the nucleus, but several of these are branched, and there 
are a few incomplete radii, so that about 13 reach the margin; lower margin crenate; lateral circuli 
coarse, not dense, parallel with the margin; apical ctenoid field very well developed, the marginal teeth 



Fig. 32.— Cynoscion regalis (Sciaeni¬ 
dae). Apical teeth. Bureau of 
Fisheries. 



Fig. 33.— Lopholatilus chamceleonticeps (Latilidae). Apical 
structures. A, normal scale; B, latinucleate scale. Bureau 
of Fisheries. 


truncate. Latinucleate scales are greatly modified, and would not be recognized as coming from the 
same fish. 

CIRRHITIDiE. Cirrhitoids. 

Cirrhitichthys maculatus Gunther from the Red Sea (M. C. Z., 3686) has large broadly rounded 
scales, about 9 mm. long and io>£ broad, with the lower margin crenate, but otherwise straight, and the 
laterobasal comers rectangular. The strong basal radii are about 12 to 14. The excessively fine lateral 



















164 


bulletin of the bureau of fisheries. 


circuli are strictly parallel with the margin, and the apical field has coarse, widely spaced longitudinal 
circuli. The apical margin carries a broad band of dusky skin, and is not distinctly dentate. This 
is certainly a peculiar scale, but my specimens are more or less latinucleate. 

Suborder Kurtoidea. 

KURTIDAJ. 

The scales, according to Boulenger, are minute and rudimentary. 

Suborder LabyrinThici. 


ANABANTIDAE Climbing perches. 


I have scales of Anabas scandens, from Lake Buhi, Philippine Islands, and A. munii from Sharb-el- 
Aish, Egypt; the latter from the British Museum. The characters of the Climbing perch, A. scandens, 



Fig. 34. — Anabas. The 
lines running down¬ 
ward are circuli. 



Fig. 35. —Anabas munii (Anabantidae). Egypt. British Museum. 


are given in the table of acanthopterygian scales above; A . munii scarcely differs. It is characteristic of 
Anabas that the basal circuli are dense, the lateral ones rather widely spaced, and those at the sides of 
the apical field strong and very far apart. The ctenoid patch is decidedly different from that of the 
percoids, and apparently less specialized. In A. munii the apical spines are broadened at base, and 
are singularly like those of Aphoristia pigra. Boulenger says the Anabantidae are closely related to the 
Ophiocephalidae, in which the scales are cycloid. Goodrich places them in a “subtribe” with the 
Osphromenidae. The Anabantidae apparently can not be derived from the percoids; they represent an 
early branch from the acanthopterygian stem. 

Suborder Holconoti. Surf-fishes. 


EMBIOTOCIDAE Surf-fishes. (PI. xxxvm, fig. 37, 38.) 

The material studied was all collected by the Albatross, as follows: Zalembius rosaceus (Jordan & 
Gilbert), above Santa Barbara Channel; Amphisticus argenteus Agassiz, St. Nicholas Island; Phanerodon 
furcatus (Girard), San Diego, Cal.; Damalichthys argyrosomus (Girard), Seattle, Wash. The scales are 




















OBSERVATIONS ON FISH SCALES. 


165 

similar, all purely cycloid, with the acanthopterygian type of basal radii. They probably represent a 
cycloid derivative from the ctenoid series, but they certainly can not be derived from the gerrid type I 
have examined. The nucleus is central or slightly above, and the basal radii are spread out fan-wise. 
The basal radii are about 15-19 in Phanerodon, 11-13 in Damalichthys , 9-10 in Zalembius, 7-10 in Amphis- 
ticus. The lateral circuli are angulate in Amphisticus and obtusely bent in Zalembius; in the large 
(8 mm. diam.) scales of Phanerodon the bending of the lateral circuli is evident near the middle, but 
becomes evanescent toward the periphery. The apical and basal cir¬ 
culi in Phanerodon are very fine and dense. 

On comparing these scales with those of the Pceciliids, which ap- 
peaf to be primitively cycloid, it is not at first evident that there is 
any characteristic difference. The Pceciliids do not show the bending 
or angulation of the lateral circuli, and their system of basal radii is 
less regular and fan-like. The general facies is distinctly different, 
yet it is difficult to point out good diagnostic characters capable of 
being expressed in words. The atherinid scale, as one would expect, 
ranks rather with the poeciliid than the embiotocid. 

Labrid and scarid scales, although cycloid, are entirely different from all these. Jordan places the 
Embiotocids in a separate suborder, Holconoti, remarking that “it contains fishes percoid in appear¬ 
ance, with much in common with the Gerrids and Sparidae, but with certain striking characteristics not 
possessed by any perch or bass. * * * The lower pharyngeals are solidly united, as in the Labrids, 
a group which these fishes resemble in scarcely any other respects. ’ ’ 

It seems just possible that the Embiotocidae, although not close to the Labridae, may agree with them 
in having had (as I certainly must suppose of Labridae) no ctenoid ancestors. In this case they would 
apparently be distant relatives of the scombroid and atherinoid series. We have, however, in the 
Cichlidae a scale development similar to that of the Embiotocidae, and certainly from ctenoid ancestors. 
(Compare the scale of Tilapia, figured in Smithsonian Miscellaneous Collections, volume 56, no. 1.) 

Suborder Chromides 

Here we return to the normal percoid type of scale. 

POMACENTRIDiE. Coral-fishes. 

I have examined the cockeye pilot, Eupomacentrus leucostictus (Muller & Tro- 
chel), from Key West, Fla. (W. C. Kendall), and Abudefduf saxatilis (Linnaeus), from 
Socorro Island (Albatross). The scales look like those of the Sparidae. They are 
broader than long, those of Eupomacentrus being extremely broad (long. 3, lat. nearly 
5 mm.). The basal radii are about 9 to n. In both genera the lateral circuli are 
slightly oblique. This is a case in which the fishes have developed very marked 
structural characters, without any material evolution in the scales. 

CICHLIILE. Cichlids. (PI. xxxix, fig. 39, 40, 41-) 

The cichlid scales much resemble those of the pomacentrids, but the lateral cir¬ 
culi are not oblique, and the submarginal apical elements, instead of being truncate, 
are obtusely pointed and spinelike, herein approaching the condition of the Ana- 
bantids. It thus becomes possible to get an idea of the evolution of the complicated and specialized 
ctenoid patch of the percoids, the stages being represented more or less accurately by the Macruridae, 
Anabantids, Cichlids, and Pomacentrids, although, of course, this arrangement does not correctly 
represent the evolution of these particular families. It is also worthy of note that Tilapia mlotica 
(figured in Smith. Misc. Coll., 56, pi. h fig- 3) has exactly the anabantid type of circuli, with widely 
spaced coarse ones at the sides of the apical area. The middle of the apical area in T. mlotica is covered 



Fig. 37. —Abudefduf 
saxati lis (Poma- 
centridae). Cte¬ 
noid structures. 
Bureau of Fish¬ 
eries. 



Fig. 36. —Eupomacentrus leucostictus 
(Pomacentridae). Ctenoid struc¬ 
tures. Bureau of Fisheries. 





bulletin of the bureau of fisheries. 


i 66 

with coarse granules or tubercles, and the scale appears to be strictly cycloid, but with a microscope 
it is possible to see minute short teeth all along the apical margin. 

I give a key for the separation of the cichlid scales now before me: 

Apical margin apparently cycloid, the rudimentary teeth microscopical. .Tilapia nilotica 

Apical margin evidently ctenoid, the ctenoid patch highly developed, the elements imbricated... i 

1. Scales not greatly broader than long; elements of ctenoid area very distinct, relatively large, 

the submarginal ones broadened basally; basal radii 8 to io (Lake Hyanuary, Brazil, 
M. C. Z., 5285; Cichla monoculus Agassiz, det. Steindachner). 

Chxtobranchopsis ocellaris Bloch & Schneider 
Scales much broader than long; elements of ctenoid area smaller. 2 

2. Nucleus much less than a third of total length from apex; scales large, about 8 mm. long and io£ 

broad; basal radii about 11; basal margin very deeply crenate (Coary, Brazil, M. C. Z., 

15516). Geophagus jurupari Heckel 

Nucleus a third of total length from apex. 3 

3. Basal radii about n or 12 (Rio Novo, Brazil, M. C. Z., 15739). 

Geophagus brasiliensis Quoy & Gaimard 
Basal radii about 16 (Lake Hyanuary, Brazil, M. C. Z., 15706). .Choeto bronchus flavescens Heckel 

On the label of the G. brasiliensis is a manuscript generic name proposed by Steindachner for this 
fish, but not published. As the fish was named by Steindachner, it is perhaps really G. steindachneri 
Eigenmann & Hildebrandt, which Steindachner confused with brasiliensis. 

The present distribution of the Cichlidae is much like that of the Characinidae, except that they occur 
in India and Madagascar, where the characinids are absent. Their northern origin is strongly suggested 
by the occurrence of a genus ( Priscacara) in the Eocene of Wyoming. This genus has ctenoid scales of 
the normal cichlid type, and numerous basal radii, closely placed in the central part of the scale. The 
character of the ctenoid area confirms the view that the genus is cichlid, not pomacentrid. 

Suborder Pharyngognathi. Eabroid fishes. 

The Pharyngognathi are variously limited by different authors. Thus Gunther (1880) includes the 
Pomacentridae, Labridae, Embiotocidae, and Chromides. Goodrich (1909) has the same series: Pomacen- 
tridae, Cichlidae, Embiotocidae, Labridae, and Scaridae. Jordan (1905) includes Labridae, Odacidae, Sipho- 
nognathidae, Scaridae (Scarichthyidae). Jordan’s arrangement is strongly supported by scale char¬ 
acters (I do not know the siphonognathid scale, however); the Gunther-Goodrich series includes forms 
with extremely diverse scales, and is surely unnatural. The scales of the true Pharyngognathi (sens. Jor¬ 
dan) are characterized by the very thin apical margin, wholly without teeth, and especially the presence 
of apical as well as basal radii. They are thus quite unlike any other acanthopterygian scales known to 
me, unless they may be associated with the Atherinidae, in which the shape and general appearance of 
the scale is quite different. Such atherinids as Chirostoma crvstallinum Jordan & Snyder (Lake Chapala, 
Mexico; J. N. Rose) and Menidia notata Mitchill show weak but evident apical radii, in the Chirostoma 
leading to a strong lobulation of the apical margin. Outside of the acanthopterygian series the pharyn- 
gognath scale is strikingly similar to that of the cyprinoids. 

LABRIDAE. Wrasses. 

Scales more or less elongate, parallel-sided, having the form seen in the cyprinid genus Labeo (see 
Biological Bulletin, vol. xx, pi. 1, fig. 8). The lateral line canals of Labrichthys are branched anteri¬ 
orly, as shown by Gunther. The regular basal radii in Pimelometopon, Emmeekia, and Coris are in 
the manner of the acanthopterygians. The species examined are Coris venusta Sauvage, Honolulu, 
H. I. (Jordan & Evermann); Emmeekia venusta (Jenkins & Evermann), Gulf of California (Albatross); 
slippery dick, Iridio bivittatus Bloch, Key West, Fla.; fathead, Pimelometopon pulcher (Ayres), Santa 
Barbara Island (Albatross); tautog, Tautoga onitis (Linnaeus), Woods Hole, Mass.; and cunner, Tau- 
togolabrus adspersus (Walbaum). 






observations on fish scales. 


167 


These may be separated by the following key: 

Inner apical circuli usually strengthened, forming wavy longitudinal ridges; apical circuli longi¬ 
tudinal; apical margin broadly thin, with only shadowy indications of radii; basal radii about 
8, and laterobasal (ending above the basal comers) one to four on each side; scales about 

ZPi mm. long and 2 broad. Pimelometopon pulcher (subfamily Harpinae) 

Inner apical circuli not thus modified. 1 

1. Scale is very large and broad, yellowish; about 13-14 mm. long and 11-12 broad; basal radii 

numerous, usually over 20. 2 

Smaller, 7 mm. or less broad. 3 

2. Apical radii very well developed, extending from nuclear region to apex. 

Iridio bivattatus a (subfamily Julidinae) 
Apical radii very poorly developed, skin of apical region very thick. 

Tautogolabrus adspersus a (subfamily Labrinae) 

3. Basal radii more than 20, laterobasal (ending above basal comers) 7 to 10; apical radii numerous 

and close together, though imperfect; lateral circuli very dense; scale very long, about 7 

mm. long and 3% wide. Coris venusta (subfamily Julidinae) 

Basal radii less than 20 (perhaps sometimes over 20, counting rudiments), laterobasal 1 to 7; 
scale not twice as long as wide b . 4 

4. Apical radii distinct; scale about 9 mm. long and 6 broad. 

Emmeekia venusta (subfamily Julidinae) 
Apical radii indistinct or imperfect; scale about 10 mm. long and 6 broad. 

Tautoga onitis (subfamily Labrinae) 


ODACID^. 


The scaie of Odax lineatus, as figured by Gunther, is entirely of the labrid type, and is very like 
that of Coris. 


SCARIDAi. Parrot-fishes. (PI. xxxix, fig. 44.) 


Scarus croicensis (Bloch) has scales differing from those of the Labridae in being short and broad, 
shield-shaped, about 6 mm. long and a little less in width. Lateral and basal circuli excessively fine; 
basal margin broadly truncate, lobed in middle, but not in the least crenulate; basal and apical radii 
very well marked, but only the inner ones reaching the nucleus; there are about 16 apical and the same 
number basal and laterobasal; apical region papillose, but the apical margin very broadly thin and 
subhyaline. A very cyprinid-looking scale. 


Suborder Squamipinnes. Scaly-fins. 

EPHIPPIDAS. Spadefishes. 

Gunther has figured the scale of Ephippus or Scatophagus muItifasciatus. It is represented as strongly 
ctenoid, with several rows of teeth; the basal radii are feebly indicated by a few broad depressions. 

CHAJTODONTIDAS. Butterfly-fishes. 

I have Chcetodon ulietensis Cuvier & Valenciennes from Apia, Samoa; C. bricei Smith, from Katama 
Bay; and Pomacanthus arcuatus (Linnaeus). The characteristic ctenoid sculpture of these genera is 
shown in figures 38 and 39. The marginal teeth in Chcetodon are very sharp, and both the teeth and the 
truncate submarginal elements have a specialized triangular area, shaped like a thorn, superimposed, 
as it were, upon their surface. All this is exactly the same in the Atlantic C. bricei as in the Pacific 
C. ulietensis, notwithstanding the great geographical separation. 

In C. ulietensis the ctenoid area is very large and well-formed in all its details; the basal radii are 
about 17; laterobasal anglesobtuse; lateral circuli very slightly oblique. (PI. xxxix, fig. 45.) 

In the Pomacanthus the ctenoid region is much modified, the broad though sharp apical teeth each 
having a very strong rib which extends more than a millimeter basad, the successive ctenoid elements 


a Superficially these scales look exactly alike. 

b In young Tautoga scales, 5 mm. long, the length is twice the width. 










bulletin of the bureau of FISHERIES. 


168 

having perhaps coalesced. The basal radii are weak, about 3 to 7, and the excessively dense lateral 
circuli are not at all oblique. 

The fishes represent two subfamilies, Chaetodontinae and Pomacanthinae. 

• Suborder SclERODERMi. Hardskin fishes. 

BAUSTIDAE. Trigger-fishes. 

The leather jacket, Balistes carolinensis Gmelin, has peculiar thickened, extremely broad scales, 
about 3X mm. long and 7 broad, the apical half covered with large tubercles, which appear to be homol¬ 
ogous with the spines of the Macruridae. These tubercles or spines are curiously suggestive of those on 



Fig. 38. —Chatodon ulie- 
tensis (Chaetodonti- 
dae). Ctenoid struc- 
tures. Bureau of 
Fisheries. 



Fig. 39. —Pomacanthus arcuatus 
(Chaetodontidae). Ctenoid 
structures. Bureau of Fish¬ 
eries. 



Stanford University. 


the scutes of Acipenser. Those along the basad margin of the tuberculate area are arranged in a regular 
row, which is angled in the middle, the very broad angle looking apicad. A quite different looking 
Balistes scale, with six large spines, is figured in the Cambridge Natural History, Fishes, page 191. 


MONACANTHIDAE. Filefishes. 

A scale of Monacanthus , of the same general type as that of Balistes, is figured in the Cambridge 
Natural History, on the page just cited. The large spines are arranged much as in the macrurids (e. g., 
Macrurus carminifer Garman). 

I have material of the orange filefish, Ceratacanthus schcepfii (Walbaum), from near Woods Hole, Mass., 
kindly given to me by Dr. E. Linton. The skin contains many minute spots of black pigment, and in 
places a fine dark blue pigment, which does not turn red in acids. The scales are shaped nearly as in Mon¬ 
acanthus and the exposed area of each has numerous large spine-like structures, one of which is much 
larger than the others. The concealed part of the scale is striate, with the appearance under the micro¬ 
scope of tree trunks closely packed, branching more or less distally. 





















OBSERVATIONS ON FISH SCALES. 


169 


Suborder Gobioidea. 

GOBIIDjE. Gobies. 

Jordan remarks that the Gobiidae have no near relations among the spiny-rayed fishes. Gunther has 
figured the scale of Gobius, and I am indebted to Dr. Jordan for material of the Japanese Mapo fuscus 
(from Tanegashima), Ctenogobius virgatulus (from Shiogama) and C. hadropterus (from Tanegashima). 
These fishes have basal radii as in the acanthopterygians, but the nucleus is at the very apex of the scale, 
and the marginal teeth form a single apical row as in the Aphredoderidae; exactly, also, as in the ctenoid 
African Characinidae. In the ctenoid African characinids the basal radii are not developed, or rather 
are represented by mere folds; in Aphredoderus they are 
very distinct, but not numerous; in the Gobiidae they are 
very numerous and close together. In the gobiids the 
relatively short (though very strongly developed) apical 
teeth are more like those of the ctenoid characinids than 
those of Aphredoderus, and the characinid Distichodus, 
with its more or less pointed or angled apical margin, 
suggests the very strong angulation of that margin seen in 
the Gobiidae. Percopsishas the apical nucleus and angled margin of the gobiids, but the marginal teeth 
are less developed, and the basal radii are absent. 

The gobiid scales before me may be separated as follows: 

Lateral margin (from apicolateral to basolateral angles) somewhat larger than apical margin of one 
side; some radii lateral (entering margin above basolateral comer); radii about 22. .Mapo fuscus 

Lateral margin shorter or not longer than apical margin of one side; no radii lateral. 1 

1. Lateral circuli quite dense; radii about 30, some imperfect. 

Ctenogobius virgatulus Jordan & Snyder 

Lateral circuli not dense; radii about 14, some imperfect. 

Ctenogobius hadropterus Jordan & Snyder 

Latinucleate scales are common and are of course much modified, though they retain the character¬ 
istic margin. 



Fig. 41. —Leptecheneis naucrates ( Echeneidae). Apical 
end to the right. Bureau of Fisheries. 


Suborder Discocephali. 

ECHENEID/E. Remoras. 

I had examined the shark sucker, Lepiecheneis naucrates (Linnaeus), collected at Woods Hole, Mass., 
and concluded that there were no scales. Dr. E. Linton, who was working on the parasites of this fish, 
suggested that scales might be found in the skin, and so it proved. The completely embedded scales 
have an elongate-lanceolate form, pointed or obtuse at the ends, length about 2% mm. The sculpture 
consists only of rather widely spaced concentric circuli. No other similar scale is known to me, 
though in the matter of sculpture (though not at all in form) the scales substantially agree with those 
of Lota. 





170 bulletin of the bureau of fisheries. 

Suborder SclEroparei. 

SCORPjENID^E. Scorpion fishes. 

In this family the scales may be fully ctenoid, or may entirely lose the teeth. 

Subfamily SEBASTINAL 

Sebastes Cuvier, rosefish. S. marinus (Linnaeus) from Woods Hole (V. N. Edwards), has small oblong 
scales with five basal radii, very widely spaced circuli, and three or four very large and stout apical 
spines (fig. 74). The apical circuli are angled in the middle. 

Sebastodes Gill. Mr. A. R. Moore very kindly sent a number of species of Sebastodes from California, 
showing that the genus has rather large scales, very strongly ctenoid, with very numerous, strong 
and crowded apical teeth, and the ctenoid patch with several rows of distinct elements (fig. 76). 
The basal radii are fairly numerous. 



Fig. 42. —Sebastes marinus (Scorpaenidae). Apical struc- Fig. 43. —Sebastodes paucispints (Scorpaenidae). 

tures. Bureau of Fisheries. California. 


Mr. Moore sent 5 . paucispinis (Ayres), S', flavidus (Ayres), S. mystinus Jordan & Gilbert, 5 . 
ruberrimus Cramer, S. constellatus (Jordan & Gilbert), S. rosaceus (Girard), S. carnatus (Jordan & Gil¬ 
bert), and S. nebulosus (Ayres), and although the scales of all these were carefully examined by 
Miss Evelyn Moore and myself, we could find no satisfactory specific characters. 


Subfamily SCORP2ENIN2E. 

Scorpcena Linnaeus. S. plumieri Bloch, from Katama Bay, has small scales a little over 1 mm. long, and 
about 1 mm. broad, with coarse but dense circuli, and about seven basal radii. The circuli fail 
in the apical field, and the margin is cycloid, with, however, occasional rudiments of minute teeth. 

Helicolenus Goode & Bean. H. dactylopterus (De la Roche), from off Woods Hole, in gulf weed, has 
comparatively large scales, oval in form, about 4 mm. long and 3 wide. They are cycloid, and 
formed much as in Scorpcena, but with about 13 basal radii. The apical field is covered with little 
tubercles, resulting from the breaking up of the apical circuli. The basal circuli are very minutely 
beaded. Jordan & Evermann state that this genus has ctenoid scales on the top and sides of the 
head, which is not true of Scorpcena. 

So far as the scales go Sebastodes should be in the most primitive of the above genera. 



OBSERVATIONS ON FISH SCALES. 


171 


C 0 TTIDA 5 . Sculpins. 

In the fossil Lepidocottus brevis (Agassiz), from the Upper Miocene at Wangen, Baden (E. Penard), 
the scales are as in the Gobiidae, with angled apical margin, a single row of marginal teeth, apical nucleus, 



Fig. 44. —Sebastodes paucispinis 
(Scorpaenidae). California. 



Fig. 45.— Prionotus strigatus 
(Triglidae). Apical struc¬ 
tures. Bureau of Fish¬ 
eries. 



Fig. 46. —Cephalacanthus volitans 
(Cephalacanthidae). A, high 
crest; B, pigment spots. Bu¬ 
reau of Fisheries. 


etc. Is it quite certain that this fish really is a cottid? Species of Lepidocottus have actually been 
described under Gobius. 

PLATYCEPHALIC. Flatheads. 


Gunther has figured the scale of Platycephalus cirrhonasus. It is of typically ctenoid character' 
with about four basal radii, but long and parallel sides, the shape suggesting the labrids. 


Suborder Craniomi. 


TRIGLIDAE. Sea robins. 


Prionotus strigatus (Cuvier & Valenciennes), the striped sea robin, from Woods Hole, has the scales 
subquadrate, about /p/ 2 mm. long and 5 broad, typically ctenoid, with the ctenoid patch large; basal 
radii about seven or eight; lateral circuli parallel with margin. The submarginal apical elements are 
very short, broader than long. 

CEPHALACANTHIDAE. Flying gurnards. 


Cephalacanthus volitans (Linnaeus), the flying gurnard, from Woods Hole, has greatly modified, 
strongly keeled scales, with the margin toothed. The form is sufficiently shown in the accompanying 
figure. There is nothing in the scales to suggest affinity between the triglids and cephalacanthids. 


Suborder Heterosomata. Flatfishes. 


I have given an account of the scales of these fishes in Proceedings of the Biological Society of Wash¬ 
ington, volume xxiv, pages 209-211; it remains now only to present some figures, and a few additional 
details. 

PLEURONECTIDAE. Flounders. 

I am indebted to Dr. F. B. Sumner for scales of Platophrys (or Rhomboidichthys) podas, from the 
Bay of Naples. In my table, in the paper just cited, they run to Platophrys constellatus , from which 
they scarcely differ. Both have traces of radial lines crossing the lateral circuli, producing a sort of 
delicate cancellation. The apical teeth in P. podas are about 7 or 8, very stout and strong. 

SOLEIDAL Soles. 

Scales of a species of Cynoglossus from Hongkong (M. C. Z., 11329) are large, about 9 mm. long 
and nearly 6 broad; strongly ctenoid on the upper (pigmented) side of the fish, strictly cycloid below. 






172 


bulletin of the bureau of fisheries. 


The basal radii are excessively numerous and close together (pi. xi,, fig. 52). The ctenoid elements are 
formed essentially as in the tongue sole, Aphoristia pigra, which belongs to the subfamily Cynoglossinae. 
A truly remarkable feature, equally developed in the cycloid and ctenoid scales, is found in the basal 
(interradial) circuli, which as they leave the radii are directed obliquely apicad, and in the middle 
third of the interradial field are broken up into minute more or less pyriform bodies. In Symphurus 
(or Aphoristia) piger the beginning of this is seen in the fact that some of the interradial sections of the 
circuli are bent and V-like. The extreme and unique modification of the basal circuli in Cynoglossus 
is important, as I think it amounts to a demonstration that Cynoglossus (with cycloid scales on the lower 
side) is not a primitive member of the Soleidae and is not connected in any way with the pleuronectids. 
The general characters of the fish also support this idea. 


Suborder J ugulares.* 

BLENNIIIUE. Blennies. 


The rock eel, Pholis gunnellus (Linnaeus), from Menemsha Bight, Mass., has extremely minute 
more or less oval cycloid scales, with the nucleus a little above the middle, very widely spaced circuli, 



Fig. 47. —A chirus lineatus (Soleidae). 
Apical structures. Bureau of 
Fisheries. 



Fig. 48. —A phorislia pigra 
(Soleidse). Apical 
structures. Bureau of 
Fisheries. 



Fig. 49.— Solea so~ 
lea (Soleidae). 
Apical struc¬ 
tures. Bureau 
of Fisheries. 


and rather widely separated radii basally and laterally. Ulvaria subbifurcata Storer, taken by Mr. V. N. 
Edwards from the stomach of a red-breasted merganser ( Merganser senator Linnaeus), has similar but 
longer scales, with the nucleus more apicad, and the 3 to 6 radii all basal. The circuli fail in the apical 
region. 

These are very degenerate scales, which do not suggest any acanthopterygian affinities. 


ANARHICHADIDiE. Wolf-fishes. 


The wolf-fish, Anarhichas lupus (Linnaeus), from Woods Hole, has small nearly circular scales, with 
central nucleus and radii almost all around, in every way very like those of Pholis. 


GADOPSIDAJ. New Zealand “ trouts.” 

Gadopsis, a fresh-water genus of New Zealand and Australia, has been figured by Gunther. The 
scale is long oval, cycloid, with regular circuli, which are not dense; nucleus a little apicad of middle; 
six strong radii. All this is very close to the blenniid Ulvaria. The fact that the three families of 


See also Proceedings Biological Society of Washington, vol. xxvi, p. 89-92. 











observations on fish scales. 


173 


Jugulares, of which the scales are known to me, agree so closely in scale characters must indicate that, 
degenerate as they are, these scales really represent an ancient type, less modified than other characters 
of the fishes on which they occur. 

Suborder Anacanthini. Gadoid fishes. 


I have discussed this series at some length in Proceedings of the Biological Society of Washington, 
volume xxiv, pages 211-212. I now offer some figures. 

GAD IDAS. Cods. 

Since the account cited above was printed I have examined scales of the European burbot, Lota 
lota (Linnaeus), from the Danube (M. C. Z. 12366), and the American burbot, L. maculosa (Le Sueur), from 




Fig. 50.— Brostnius brosme (Gadidae). Sculptural details, submarginal region. Bureau of Fisheries. Smaller figure shows 

sculpture of a latinucleate scale near middle. 

Erie, Pa. (Bureau of Fisheries). This genus, typical of the subfamily Lotinae, has extremely minute 
circular to suboval scales, with nucleus central or almost; coarse, widely separated circuli, and no radii. 
It is, however, to be noted that the circuli are crenate or denticulate on the inner margin, a relic of the 



Fig. 51.— Melanogrammus aeglepinus (Gadi- 
dse). Details of sculpture, submarginal 
region. Bureau of Fisheries. 



Fig. $2.—C<Blorhynchus caribbceus, and spine of Macrurus bairdit (Macruri- 
dse). U. S. National Museum. 


condition so well marked in Brosmius. I am quite unable to find any difference between the scales of 
the European and American species. 

A scale of Urophysis regius is figured on plate XL (fig. 51.) 

MACRURIDAS. Grenadiers. (PI. XL, fig. 48.) 


Dr. S. Garman (Mem. Mus. Comp. Zool., vol. xxiv) has figured the scales of a number of species of 
Macrurus, namely M. barbiger Garman, M. bulbiceps Garman, M. bucephalus Garman, M. liraticeps 























174 


bulletin of the bureau of fisheries. 


Garman, M.fragilis Garman, M. tenuicauda Garman, and M. carminifer Garman. M. barbiger has no 
teeth whatever; M.fragilis is represented with a single little tooth. M. bulbiceps has very many little 
spines in the apical field; M. carminifer has very large spines. The figure of M. tenuicauda looks like a 
latinucleate scale. 

Order PEDICULATI. 

ANTENNARIIDjE. Fishing-frogs. 

Dr. Garman, in the work just cited, figures the spiniferous scales of Chaunax coloratus Garman. In 
the Cambridge Natural History, Fishes, page 191, is a figure of the scale of Antennarius hispidus. 

OGCOCEPHALIDAL Batfishes. 

In the Cambridge Natural History, on the page just cited, is a figure of the spine-bearing scale of 
Ogcocephalus or Malthe vespertilo (Linnaeus). 




Bull. U. S. B. F., 1912. 


Plate XXXII. 



5 6 
Fig. 1.—Placopharynx duquesnii. Cherokee, Iowa (S. E. Meek). 

Fig. 2.—Acanthorhodeus tsenianalis. Shanghai (Swinhoe). The wavy apical radii are not well shown. 
Fig. 3.—Algansea sallaei. Guanajuato, Mexico (A. Dug£s). 

Fig. 4.—Chela paralaubuca. British Museum. 

Fig. 5.—Chondrostoma meigii. San Domingo de Silos, Burgos, Spain (Gonzales). 

Fig. 6.—Nocotnis kentuckiensis. Stone River, Tennessee. 












Bui,i,. U. S. B. F., 1912. 


Plate XXXIII 



Fig. 7.— Iyuciosoma trinema. Upper Baram River (C. Hose). 

Fig. 8 .—Notemigonus chrysoleucus. Falmouth, Mass. 

Fig. 9.—Rohiita lineata. Sittang River (E. W. Oates). British Museum. 
Fig. 10.—Scaphiodon muscatensis. Muscat, Arabia. British Museum. 
Fig. 11.—Schizothorax intermedius. Kashgar. British Museum. 

Fig. 12.—Semiplotus macclellandi. Assam (F. Day). British Museum. 






















































- 








































































■ 










' 

*■ 



























































Bull. U. S. B. F., 1912. 


Plate XXXIV. 



Fig. 13.—Capoeta fratercula. Persia. British Museum. 

Fig. 14.—Culter erythropterus. R. Keroulen, Mongolia (Chaffanjon). British Museum. 
Fig. 15.—L,eptobarbus hoevenii. Tinjar River (C. Hose). British Museum. 

Fig. 16.—Oreinus grahami. British Museum. 

Fig. 17.—Homaloptera maculata. Khassya (Dr. Jerdon). British Museum. 






























- «■ . 




















. 








































































Bull. U. S. B. F. 


1912 


Plate XXXV. 



22 21 

Fig. 18.—Clupanodon pseudohispanicus. Woods Hole, Mass. 
Fig. 19.—Synodus foetens. Galveston, Texas (Evermann). 
Fig. 20.—Lucius lucius. Toledo, Ohio (Rutter). 

Fig. 21.—Fundulus tnajalis. Latinucleate scale. 

Fig. 22.—Fundulus heteroclitus. Woods Hole, Mass. 













Buff. U. S. B. F., 1912. 


PFATE XXXVI 





26 


Fig. 23.—Mollienisia latipinna. Gordons Pass, Florida (Henshall). 

Fig. 24.—Scombresox saurus. Woods Hole Collection. 

Fig. 25.—Chirostoma crystallinum. Fake Chapala, Mexico (J. N. Rose). 

Fig. 26.—Holocentrum laticeps. Kaui, H. I. Museum of Comparative Zoology. 
Fig. 27.—Caranx hippos. Woods Hole Collection. 



















































































* 

































































































































Bull. U. S. B. F., 1912 


Plate XXXVII. 



Fig. 28.—Mesogonistius chaetodon. Trenton, N. J. 

Fig. 29.—Ambloplites rupestris. Huntington, Tenn. 

Fig. 30.—Archoplites interruptus. San Francisco, Cal. 

Fig. 31.—Centropristes striatus. Woods Hole, Mass. 

Fig. 32.—Plesiops corallicola. Ebon Islands. Museum of Comparative Zoology. 
Fig. 33.—Orthopristis chalceus. Guaymas or Clarion Island. (Albatross). 






































































































































































































































Bull. U. S. B. F 


1912 


Plate XXXVIII 



34 





37 38 

Fig. 34.— Box vulgaris. Vienna Museum. 

Fig. 35— Smaris sp. Trieste. 

Fig. 36.—Gerres gula. Brazil. Museum of Comparative Zoology 
FKi. 37 -—Amplnsticus argenteus. St. Nicholas Island. (Albatross.) 

Fig. 38.—Zalembius rosaceus. Above Santa Barbara Channel. (Albatross ) 























































































Bui,i,. U. S. B. F 


Plate; XXXIX. 


1912. 



44 43 

Fig. 39.—Geophagus brasiliensis. Rio Novo, Brazil. 

Fig. 40.—Cichla monoculus. Bake Hyanuary, Brazil. Museum of Comparative Zoology 
Fig. 41.—Chsetobranchus flavescens. Bake Hyanuary, Brazil. 0 

Fig. 42.—Pimelometopon pulcher. Santa Barbara Islands. (Albatross ) 

Fig. 43.—Kmmekia venusta. Gulf of California. (Albatross.) 

Fig. 44.—Scarus croicensis. Woods Hole Collection. 

Fig. 45.—Chaetodon ulietensis. Apia, Samoa. (Jordan.) 



. • 






















Bu ia. U. S. B. F., 1912. 


Plate XL. 



50 51 52 

Fig. 46.— Helicolenus dactylopterus. Off Woods Hole. 

Fig. 47.—Prionotus strigatus. Woods Hole, Mass. 

Fig. 48.—Macrurus sp. Albatross station 2426. 

Fig. 49.—Lota vulgaris. Danube. Museum of Comparative Zoology. 

Fig. 50.—Gadus callarias. Woods Hole Collection. 

Fig. 51.—Urophycis regius. Woods Hole, Mass. 

Fig. 52.—Cynoglossus sp., upper side. Hongkong. Museum of Comparative Zoology. 















































































































































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LRBAp'U 


































































